“Your Bitcoins Shall Pay the Forfeit of the Peace”: Why What the Government Chooses To Do With Seized Silk Road Bitcoins Matters

By Derek A. Dion*

I.  The Silk Road Bust

On October 2, 2013, the FBI arrested the “Dread Pirate Roberts” and shut down the Silk Road—a website that served as the Amazon.com of the criminal underworld, selling any matter of illegal drugs online.[1]  Dread Pirate Roberts, also known as Ross Ulbricht, purportedly founded the website.  Silk Road could only be accessed by using The Onion Router, or TOR, which served to anonymize the buyers and vendors on the website.  To further obscure the identities of those engaged in the black market, Silk Road did not make trades in U.S. Dollars or any other government currency.  Instead, the website dealt in Bitcoins—an electronic currency that can be used relatively anonymously.  When the FBI shut down the Silk Road, it immediately seized 26,000 Bitcoins from various vendors on Silk Road and seeks to seize another 600,000 Bitcoins from the Dread Pirate Roberts himself.[2]

“Bitcoin is an electronic form of currency unbacked by any real asset and without specie, such as coin or precious metal.”[3]  Bitcoin exchanges allow users to trade the e-currency for legal tender.  An algorithm regulates the Bitcoin supply, monitoring the peer-to-peer network and the number of coins in the system.  Bitcoins are kept in electronic wallets and accessed using a combination of public and private keypairs, effectively serving as a password.  Bitcoin’s use is questionably legal,[4] and the currency is used by a small community of dedicated users.

As Bitcoins are electronic, the FBI cannot “seize” them the way that it could traditional currency.[5]  Instead, the FBI must seize the servers that hold the wallets on Silk Road’s website or have access to the private keypairs of the illicit Bitcoins.  The FBI has yet to publicly confirm what it will do with the seized Bitcoins.  It has suggested that it may liquidate them after the judicial process is over.[6]  What the FBI chooses to do with the seized Bitcoins matters.  It will serve as a signal to the Bitcoin community regarding whether the U.S. government sees Bitcoin as contraband in-and-of itself or merely an otherwise legal asset that was illegally gained from a website that sells drugs.

This Column’s purpose is to recommend that the FBI liquidate the Bitcoins instead of destroying or freezing them.  It will begin with an examination of the statutes that govern how the FBI may use or dispose of assets under forfeiture law.  The Column will next address the effect that the Silk Road bust had on Bitcoin prices and what that suggests about how the market perceives the currency’s value.  Finally, this Column will examine the implications of government action on Bitcoin.

II.  Forfeiture Law

Statutes and regulations govern what an agency may do with seized property.  The property first goes through a forfeiture proceeding, either criminal or civil, which determines the final disposition of a citizen’s rights with regards to an asset.[7]  Once the asset has been forfeited to an agency, its disposition depends on the type of asset.  For example, when the government seizes currency, the agency has permission to keep the forfeited property for its official use.[8]  For most assets, including foreign currencies, the agency may choose whether it keeps, sells, or destroys the property.  For example, the FBI could trade seized foreign currency for U.S. Dollars through a currency exchange.  Alternatively, the FBI could destroy property for which it has no use.

For certain assets, though, Congress gives the agency less freedom.  For example, forfeited drug paraphernalia must be destroyed unless it is used for law enforcement or educational purposes.[9]  This, of course, makes sense.  It would be bad policy to allow say, the DEA, to be in the business of selling drug paraphernalia to the public, even if there is a willing market and the DEA could make money on the transaction.

Some items are treated like contraband even when they are not.  For example, an agency is not permitted to sell forfeited firearms to the public.[10]  If the agency does not sell the firearms to another agency and does not plan to keep them for law enforcement or educational purposes, they must be destroyed.  Alcohol is treated similarly.[11]  Note that firearms and alcohol, unlike drug paraphernalia, are not illegal per se.  However, Congress has concluded that it is bad policy for the government to partake in selling firearms and alcohol back to the public because those items are legally and morally controversial.

When it comes to the Silk Road Bitcoins, the FBI is free to take whatever action it likes.  The U.S. Code and Code of Federal Regulations make clear that assets not specifically excepted (such as firearms, alcohol, and drug paraphernalia) may be liquidated by an agency.  But the question is: Should the FBI publicly sell the Bitcoins back to the public when Bitcoin’s legal status as a currency remains unclear or should the FBI treat Bitcoins more like it treats non-contraband exceptions like alcohol or firearms?  To answer this question effectively, the government must first consider where the value of Bitcoin lies.

III.  What Governs Bitcoin’s Value?

The price of Bitcoin was immediately affected by the closure of Silk Road.  Prior to the shut down on October 2, Bitcoin’s price on Mt. Gox,[12] one of the largest and most popular Bitcoin exchanges, was $145.70 per coin.[13]  After the FBI announced Ross Ulbricht’s arrest, the price plunged to $109.76.  However, by the end of the next trading day, the price had rebounded to $124.00.  Since then, Bitcoin’s price has begun to soar far above its open on October 2.[14]

It is easy to hazard why Bitcoin’s price initially fell.  The FBI alleged that Silk Road generated sales worth approximately 9.5 million Bitcoins compared to the approximately 11.8 million Bitcoins in circulation.  Obviously, Silk Road played a significant role in the circulation of Bitcoins in the system.  But what explains Bitcoin’s recovery after the crash?  Here are three potential answers:

A.  Users Believe Bitcoin’s Legal Status Is Stable

One reason Bitcoin crashed may be the assumption that the FBI would declare Bitcoin illegal after it shut down Silk Road.  In fact, the FBI has done the opposite.  By suggesting it may liquidate the Bitcoins, the FBI sends a signal that it does not consider Bitcoin contraband.  The recovery could be due to the fact that the FBI had an opportunity to declare Bitcoin illegal and did not.  One of the main reasons Bitcoin is unstable as a currency is the market’s concern that the currency may be considered illegal.

B.  Bitcoin Has Value Beyond Criminal Activity

Another view of the crash is premised on the notion that Bitcoin’s primary value is fostering illegal activity.  When Silk Road was shut down, it destroyed a major source of value for Bitcoin, thus causing a drop in price.  However, if this premise was true, what explains the recovery in price?

There is no doubt that Bitcoin has vast potential for advancing criminal behavior.[15]  But if the market truly had believed that Bitcoin’s value was its capacity for criminal behavior, its price would have gone down with Silk Road’s closure and would likely have remained there.  But instead, the recovery suggests that the market believes in value beyond illegal activity.  And if that is true, removing Silk Road creates separation between Bitcoin and clear, well-known illegal behavior.

C.  Supply Is Restricted

The final theory explaining Bitcoin’s recovery relies on supply and demand.  The FBI may end up removing approximately 625,000 Bitcoins from the marketplace.  As noted above, there are approximately 11 million Bitcoins in existence.  Therefore, the FBI could remove as much as five or six percent of the entire market of Bitcoins.  Thus, by reducing the supply of Bitcoins in the system, one would expect the price to go up.

These three explanations should inform government action.  The FBI must understand that the market may see value in Bitcoin beyond its criminal uses, the volatility of Bitcoin can be quelled by regulating e-currency without outlawing them, and the FBI has seized enough currency to affect prices.

IV.  What Government Action “Says” to the Market

No matter how the FBI decides to dispose of the seized Bitcoins, it will telegraph a message to the Bitcoin market.  Some will argue that the FBI may not mean to “say” anything with an action, but that is not the point.  No matter what the FBI does, the niche community of Bitcoin users will interpret its action as a statement on the legitimacy and viability of the currency.  The FBI has three options: sell the Bitcoins, destroy the Bitcoins, or keep the Bitcoins.

A.  Option 1: Sell

The FBI could trade the Bitcoins for U.S. Dollars on an exchange.  This option communicates to the market that the FBI does not classify Bitcoin as contraband and demonstrates non-active acceptance of the currency.  But a massive, unstructured sell-off will cause price fluctuations to an already unstable currency.  Also, the FBI could face criticism for liquidating Bitcoin if it must use exchanges that are generally unregulated.[16]

B.  Option 2: Destroy

The FBI’s second option is to destroy the seized Bitcoins.  This signals to the market that the FBI views Bitcoin as contraband or semi-contraband (such as liquor or guns).  It also wastes millions of dollars that the FBI could claim for the seizure.  Additionally, as a practical matter, the Bitcoin system is designed to recognize coins in the system and accordingly release new coins at a particular decreasing rate.  In effect, destroying a significant number of coins will simply cause the system to recognize the loss and adapt accordingly.

C.  Option 3: Keep

Finally, the FBI could keep the Bitcoins indefinitely.  Such a gesture would signal to the market that the government is either planning on keeping the Bitcoins to manipulate the market, it plans on eventually seizing all Bitcoins in the system, or it is simply unsure of what it should do.  In either case, this option would leave the Bitcoin market unsettled as it waits to see what the FBI will do.

V.  Recommendation: “Sell”

The FBI should follow through with its earlier comment and liquidate the seized Bitcoins at the end of judicial proceedings.  This author has argued before that Bitcoin should not be treated as contraband per se, and, instead, federal and state governments should pursue viable regulation, particularly of the Bitcoin exchanges.[17]  The goal should be a stable currency used for purposes outside illegal behavior.  To encourage this, the FBI should publicly announce a structured cash-out of the Bitcoin, so as to disturb the market as little as possible.  It should also only deal with exchanges that are licensed as money service businesses and presently comply with FinCEN.  Destroying the Bitcoins wastes value and unnecessarily treats the coin as contraband.  Keeping the seized coins unsettles a nascent and niche market that the government should instead work to stabilize.  This proposal gives the FBI the opportunity to capture the value that it seized from the Silk Road bust, while also signaling to the market that the government seeks to create a stable and legal Bitcoin marketplace.


* Derek Dion is in the final year of a joint-degree JD/MBA program at University of Illinois. He thanks the Illinois Journal of Law, Technology & Policy for their willingness to publish a follow up Bitcoin piece.

[1] Andy Greenberg, End of the Silk Road: FBI Says It’s Busted the Web’s Biggest Anonymous Drug Black Market, Forbes (Oct. 2, 2013, 12:35 PM), http://www.forbes.com/sites/andygreenberg/2013/10/02/end-of-the-silk-road-fbi-busts-the-webs-biggest-anonymous-drug-black-market/.

[2] Alex Hern, FBI Struggles to Seize 600,000 Bitcoins from Alleged Silk Road Founder, Guardian (Oct. 7, 2013, 6:31 AM), http://www.theguardian.com/technology/2013/oct/07/fbi-bitcoin-silk-road-ross-ulbricht.

[3] SEC v. Shavers, No. 4:13-CV-416, 2013 WL 4028182, at *1 (E.D. Tex. Aug. 6, 2013).  The criminal case against the Dread Pirate Roberts is United States v. Ulbricht, 13-mg-023287 (S.D.N.Y. 2013), and the civil forfeiture case is United States v. Ulbricht, 13-cv-06919 (S.D.N.Y. 2013).

[4] I have written about Bitcoin more extensively in another article that addressed legal and regulatory challenges.  See generally Derek A. Dion, I’ll Gladly Trade You Two Bits on Tuesday for a Byte Today: Bitcoin, Regulating Fraud in the e-Conomy of Hacker-Cash, 2013 U. Ill. J.L. Tech. & Pol’y 165.

[5] Adam Gabbat & Dominic Rushe, Silk Road Shutdown: How Can the FBI Seize Bitcoins?, Guardian (Oct. 3, 2013, 9:40 AM), http://www.theguardian.com/technology/2013/oct/02/bitcoin-silk-road-how-to-seize.

[6] Kashmir Hill, The FBI’s Plan for the Millions Worth of Bitcoins Seized from Silk Road, Forbes (Oct. 4, 2013, 3:16 PM), http://www.forbes.com/sites/kashmirhill/2013/10/04/fbi-silk-road-bitcoin-seizure/.

[7] See 18 U.S.C. § 981 (2006) (civil); 18 U.S.C. § 982 (criminal).

[8] 40 U.S.C. § 1306(c).

[9] 21 U.S.C. § 863(c).

[10] 26 U.S.C. § 5872.

[11] 26 U.S.C. § 5688(a)(2).

[12] Bizarrely, Bitcoin has different prices on different exchanges, which would seem to lead to an easy arbitrage opportunity.  However, the differing prices may depend on the liquidity of the exchange.  Donald Marron, Do Bitcoins Violate a Fundamental Economic Law?, Christian Sci. Monitor (Sept. 3, 2013), http://www.csmonitor.com/Business/Donald-Marron/2013/0903/Do-bitcoins-violate-a-fundamental-economic-law.

[13] Alex Hern, Bitcoin Price Plummets After Silk Road Closure, Guardian (Oct. 3, 2013, 11:41 AM), http://www.theguardian.com/technology/2013/oct/03/bitcoin-price-silk-road-ulbricht-value.

[14] Emily Spaven, Bitcoin Price Soars to Highest Level Since April Bubble, CoinDesk (Oct. 21, 2013, 5:53 PM), http://www.coindesk.com/bitcoin-price-soars-highest-level-since-april-bubble/.

[15] Dion, supra note 4, at 183–87.

[16] For example, Mt. Gox’s Dwolla account was seized by the Department of Homeland Security via court order from the District of Maryland for operating as a money-transmitting business without a license.  Vitalik Buterin, MtGox’s Dwolla Account Seized for Unlicensed Money Transmission, Bitcoin Mag. (May 16, 2013), http://bitcoinmagazine.com/4641/mtgoxs-dwolla-account-seized/.  Mt. Gox later received a money transmitter license from the U.S. Department of the Treasury’s Financial Crimes Enforcement Network (FinCEN).  Vitalik Buterin, MtGox Gets FinCEN MSB License, Bitcoin Mag. (June 29, 2013), http://bitcoinmagazine.com/5560/mtgox-gets-fincen-msb-license/.

[17] For example, by requiring exchanges to record certain personal information of those who trade through them.

Digital Seizures: Why Wurie and Riley May Not Adequately Resolve Remote Destruction of Evidence

Digital Seizures: Why Wurie and Riley May Not Adequately Resolve Remote Destruction of Evidence

By Kevin Lammers*


Later this term, the Supreme Court will decide whether or not to grant certiorari in two cases involving the search of cell phones by law enforcement pursuant to the search-incident-to-arrest doctrine.[1]  The prevailing view amongst legal commentators is that the Court will grant certiorari in one of these cases to resolve whether, amongst other issues, these cell phone searches fall under the exigent circumstances exception to the Fourth Amendment’s warrant requirement.[2]  Because the Supreme Court has never applied this exception to the remote destruction of evidence—such as deleting iPhone data from another device—these cases will require the Justices to engage in a delicate balancing act between an individual’s right to the privacy of their cell phone’s contents and the necessity of law enforcement to preserve digital evidence.  The following discussion will illuminate one possible solution to that balancing act.


The issues in Wurie and Riley are particularly difficult to resolve because the exigent circumstances doctrine was created at a time when remote destruction of evidence was not possible.  Cloud computing technology (and the Internet in general) has introduced the possibility that digital evidence (e-mails, documents, text messages) might be removed from a computer without the suspect having access to that physical computer.  Seizure of the item containing the evidence—traditionally viewed as a less intrusive method for preserving evidence[3]—does not resolve the possibility that a suspect might destroy digital evidence remotely.  This is particularly problematic since law enforcement officers are increasingly relying on digital evidence to build their cases and investigate possible suspects.[4]

A variety of methods currently exist for deleting digital data from computers, tablets, and smartphones.  For example, Apple has given iPhone users the ability to erase information from their device in the event that they lose it.[5]  However, the First Circuit in Wurie argued rather convincingly that concerns about remote wiping of cell phones are overstated.  The court identified three common procedures that undermine the use of remote destruction of evidence as justification for a search: (1) turn the phone off (or remove the battery); (2) place the phone in a Faraday enclosure (which blocks wifi signals); and (3) immediately copy the cell phone’s contents onto another device.[6]  These same three procedures were also referenced by the defendant in Riley.[7]  Due to the level of intrusiveness of these three procedures, they are better understood as digital seizures rather than searches.  While these less-intrusive procedures undercut the rationale for a full-blown search justified by destruction of evidence, they do not address the destruction of files stored remotely.

In the case of more complex digital evidence, Microsoft’s latest version of Office utilizes “SkyDrive” to allow users to store and retrieve documents remotely.[8]  This type of remote deletion operates differently from the remote “wiping” of iPhone data.  Since the files on SkyDrive are stored remotely, digitally seizing a device with access to them does not prevent their destruction.  For example, if a law enforcement officer were to remove the battery of an iPad (or place it in a Faraday enclosure) with access to SkyDrive files, the SkyDrive user would still be able to completely erase those files by accessing them from another device.  Thus, even with the ability to digitally seize the contents of a physical device, the government can still argue that these searches are justified to identify what, if any, digital evidence a user has stored remotely.


Both the First Circuit in Wurie and the defendant in Riley have thus far neglected to address the problems posed by remote storage of digital evidence.  Since both cases involve the search of cell phones rather than personal computers or tablets, it is likely that the parties to those cases failed to consider destruction of digital evidence beyond remote wiping of data.  However, cell phones contain the same level of access to data on SkyDrive and Google Drive as traditional computers.  Because of this, the government’s argument that a warrantless search is necessary to prevent destruction of such data holds up against the three types of digital seizures referenced by the First Circuit and the defendant in Riley.  Since the remote storage of digital evidence is largely going unnoticed by the parties to these cases, there is a legitimate chance that the Supreme Court could create a rule for these types of searches that is not readily applicable to data on SkyDrive and Google Drive.  This problem illuminates why the Supreme Court should fashion a rule for digital searches and seizures that accounts for the possibility of destruction of evidence in any form or fashion, whether remote or local.

Such a result is foreshadowed by the Western District of Washington’s discussion of remotely-stored data in In re Edward Cunnius.[9]  It warned that digital devices are best viewed as “portals” under the Fourth Amendment, containing not only local files, but also all information stored remotely or “on the internet.”[10]  The Supreme Court should note that the types of seizures contemplated by the parties in Wurie and Riley fail to capture data retained within the portal of a digital device.  Similarly, the Ninth Circuit theorized about the possible implications of cloud computing on Fourth Amendment doctrine, albeit in dicta:

In the “cloud,” a user’s data, including the same kind of highly sensitive data one would have in “papers” at home, is held on remote servers rather than on the device itself.  The digital device is a conduit to retrieving information from the cloud, akin to the key to a safe deposit box.  Notably, although the virtual “safe deposit box” does not itself cross the border, it may appear as a seamless part of the digital device when presented at the border.  With access to the cloud through forensic examination, a traveler’s cache is just a click away from the government.[11]

Because the petition in Riley and the First Circuit’s opinion in Wurie fail to address this technology as applied to digital seizures, there is a significant chance that the Supreme Court will not reach the issue—an issue with a potentially dramatic impact on the Fourth Amendment’s application to digital devices.


With an opportunity to consider remote destruction of digital evidence, the Supreme Court should take care to craft a rule that will be applicable to the next generation of digital instruments.  One commentator has suggested that the best solution is to fashion an objective test for courts to apply to exigent computer searches:

[An officer must testify to] specific and articulable facts, known to the officer at the time of the search, demonstrating that the specific cell phone was at risk of remote deletion of potential evidence.  Additionally, the officer must further testify that there were no preventative measures available to him at the time of the search which could secure any evidence potentially stored on the cell phone.[12]

As an example of a generally-applicable solution, the above test hints at the possibility that courts will likely become well-acquainted with not only the three types of digital seizures discussed by the Wurie Court, but other forms of digital seizure designed to halt the destruction of remotely-stored data.

Using the example of SkyDrive, Microsoft may be able to access files or halt the destruction of files stored on a user’s SkyDrive.  In fact, its Windows Live Services Agreement hints at this possibility, albeit with reference to traditional legal devices such as subpoenas.[13]  Without a court order, there could still be a requirement—under 18 U.S.C. § 2703—that Microsoft (or Google) actually preserve a user’s content suspected of having evidentiary value: “A provider of wire or electronic communication services or a remote computing service, upon the request of a governmental entity, shall take all necessary steps to preserve records and other evidence in its possession pending the issuance of a court order or other process.”[14]  The authority to order a third-party to preserve digital content is particularly important because, according to one source, the recovery of deleted content on browser-based e-mail systems (such as Gmail) is a complex task at best.[15]  While this might be unnecessary when police have probable cause to believe a device contains digital evidence (where a telephonic warrant might suffice), there are circumstances where a temporary seizure could be justified based on something less than probable cause.[16]  Halting the destruction of digital information is not necessarily even a “seizure” of that data, which may be why 18 U.S.C. § 2703(f) has never been subjected to a Fourth Amendment challenge.  The user still has access to content seized pursuant to § 2703, but no ability to edit or delete it.  Arguably, halting the destruction of potential digitized evidence implicates no privacy concerns under existing Fourth Amendment jurisprudence.[17]


As the nine Supreme Court Justices (most likely) debate whether or not Wurie’s or Riley’s Fourth Amendment rights were violated, they should keep in mind that new and emerging technologies provide just as many solutions as they do Fourth Amendment problems.  Section 2703 is just one example of how exigent searches of electronic devices might be better handled by law enforcement’s reliance on similar technologies to address specific technological exigencies.  The three digital seizure methods suggested by the Wurie Court disguise a larger problem that remotely-stored and remotely-wiped evidence presents.


* J.D. Candidate, University of Illinois College of Law, expected 2014.  B.A. Psychology and Drama, University of Arkansas, 2010.  I thank the Recent Developments Editor at the Journal of Law, Technology and Policy, Angie Nizio, for her advice and attention to this piece.

[1] United States v. Wurie, No. 11-1792, 2013 WL 2129119 (1st Cir. 2013); California v. Riley, No. D059840, 2013 WL 475242 (Cal. Ct. App. 2013).

[2] See, e.g., Dana Liebelson, Will the Supreme Court Stop Cops from Reading Your Text Messages?, Mother Jones (Sept. 17, 2013, 3:00 AM), http://www.motherjones.com/politics/2013/09/police-cell-phone-search-warrant-supreme-court (quoting Alan Butler: “It’s very likely that the Supreme Court will grant certiorari and review the issue (either in Riley or Wurie). If the Court does not take one case, it will likely take the other.”).

[3] Segura v. United States, 468 U.S. 796, 806 (1984) (“Recognizing the generally less intrusive nature of a seizure, the Court has frequently approved warrantless seizures of property, on the basis of probable cause, for the time necessary to secure a warrant, where a warrantless search was either held to be or likely would have been held impermissible.” (citations omitted)).

[4] See Declan McCullagh, Cops to Congress: We Need Logs of Americans’ Text Messages, CNET (Dec. 3, 2012, 9:00 AM), http://news.cnet.com/8301-13578_3-57556704-38/cops-to-congress-we-need-logs-of-americans-text-messages/ (“As the popularity of text messages has exploded in recent years, so has their use in criminal investigations and civil lawsuits.”).

[5] iCloud: Erase Your Device, Apple Support (Sept. 18, 2013), http://support.apple.com/kb/PH2701.

[6] Wurie, 2013 WL 2129119, at *9.

[7] Petition for Writ of Certiorari at 22–23, Riley, 2013 WL 475242, (No. 13-132).

[8] SkyDrive, Microsoft, http://windows.microsoft.com/en-us/skydrive/download (last visited Oct. 7, 2013); see also File Deletion and Recovery Policy, Google Drive, https://support.google.com/drive/answer/2405957?hl=en (last visited Oct. 7, 2013) (“Anything permanently deleted from Google Drive can’t be recovered.”).

[9] In re Edward Cunnius, 770 F. Supp. 2d 1138, 1144–45 (W.D. Wash. 2011).

[10] Id. at 1145 (“All data on the internet is both separate and one.”).

[11] United States v. Cotterman, 709 F.3d 952, 965 (2013).

[12] Mireille Dee, Note, Getting Back to the Fourth Amendment: Warrantless Cell Phone Searches, 56 N.Y.L. Sch. L. Rev. 1129, 1162 (2011–12).

[13] See Microsoft Services Agreement, Windows Live (Aug. 27, 2012), http://windows.microsoft.com/en-us/windows-live/microsoft-services-agreement (describing, in Sections 5.2 and 5.3, how the user consents to Microsoft accessing and preserving their content).

[14] 18 U.S.C. § 2703(f)(1) (2006).

[15] See Sandy Boucher & Barry Kuang, Email Evidence – Now You See It, Now You Don’t!, Forensic Focus, http://www.forensicfocus.com/email-evidence-now-you-see-it (last visited Oct. 7, 2013) (“In a recent case, we were able to recover some very recent emails from a system using Windows Live Hotmail but older messages were gone and even those recovered from unallocated space were fragmented and hard to use.”).

[16] See, e.g., Terry v. Ohio, 392 U.S. 1 (1968) (holding that police may temporarily detain a person and his or her belongings based on reasonable suspicion).

[17] See Warden v. Hayden, 387 U.S. 294, 305–06 (1967) (“And with particular relevance here, we have given recognition to the interest in privacy despite the complete absence of a property claim by suppressing the very items which at common law could be seized with impunity: stolen goods; instrumentalities; and contraband[.]” (citations omitted)).