As regular readers know, I am very interested in the scope of the plain view exception for computer searches. In physical searches, if the government comes across evidence unrelated to the search it is lawfully conducting, the government can seize that evidence as long as its incriminating nature is immediately apparent. I have argued that this rule is troublesome in the context of digital searches because everything comes into plain view in computer searches. A computer warrant for anything becomes a warrant for everything, making every computer warrant a general warrant in practice. To counter that dynamic, I have argued that the plain view exception should not apply to digital searches. See Orin Kerr, Searches and Seizures in a Digital World, 119 Harv. L. Rev. 531 (2005).

The Fourth Circuit rejected that argument in United States v. Williams, 592 F.3d 511 (4th Cir. 2010), where it held that the plain view exception should apply in the same way to digital searches as it applies to physical searches. As I understand the Fourth Circuit’s view, the government can look for anything on a hard drive if it has a warrant and keep anything that comes up. Opening any file is permitted because it might contain evidence in the warrant, and all evidence can be used because it has come into plain view under the traditional plain view test. The Fourth Circuit concluded that the differences between computer searches and physical searches did not justify a different approach to plain view:

At bottom, we conclude that the sheer amount of information contained on a computer does not distinguish the authorized search of the computer from an analogous search of a file cabinet containing a large number of documents. As the Supreme Court recognized in Andresen, “[T]here are grave dangers inherent in executing a warrant authorizing a search and seizure of a person’s papers that are not necessarily pres- ent in executing a warrant to search for physical objects whose relevance is more easily ascertainable.” 427 U.S. at 482 n.11. While that danger certainly counsels care and respect for privacy when executing a warrant, it does not prevent officers from lawfully searching the documents, nor should it undermine their authority to search a computer’s files. See United States v. Giberson, 527 F.3d 882, 888 (9th Cir. 2008) (holding that “neither the quantity of information, nor the form in which it is stored, is legally relevant in the Fourth Amendment context”). We have applied these rules successfully in the context of warrants authorizing the search and seizure of non-electronic files, see Crouch, 648 F.2d at 933-34, and we see no reason to depart from them in the context of electronic files.

In light of that, I was very interested to see the Second Circuit’s decision today in United States v. Galpin. First, the opinion agrees that the scope of computer searches raises special problems:

The potential for privacy violations occasioned by an unbridled, exploratory search of a hard drive is enormous. This threat is compounded by the nature of digital storage. Where a warrant authorizes the search of a residence, the physical dimensions of the evidence sought will naturally impose limitations on where an officer may pry: an officer could not properly look for a stolen flat-screen television by rummaging through the suspect’s medicine cabinet, nor search for false tax documents by viewing the suspect’s home video collection. Such limitations are largely absent in the digital realm, where the size or other outwardly visible characteristics of a file may disclose nothing about its content. As the Ninth Circuit has explained, because there is currently no way to ascertain the content of a file without opening it and because files containing evidence of a crime may be intermingled with millions of innocuous files, “[b]y necessity, government efforts to locate particular files will require examining a great many other files to exclude the possibility that the sought-after data are concealed there.” United States v. Comprehensive Drug Testing, Inc., 621 F.3d 1162, 1176 (9th Cir. 2010) (en banc) (per curiam). Once the government has obtained authorization to search the hard drive, the government may claim that the contents of every file it chose to open were in plain view and, therefore, admissible even if they implicate the defendant in a crime not contemplated by the warrant. There is, thus, “a serious risk that every warrant for electronic information will become, in effect, a general warrant, rendering the Fourth Amendment irrelevant.” Id. This threat demands a heightened sensitivity to the particularity requirement in the context of digital searches.

After ruling that the warrant in that case was in valid and remanding for further proceedings, the Second Circuit offered the district court guidance on how to apply the plain view exception on remand:

[T]he district court’s review of the plain view issue should take into account the degree, if any, to which digital search protocols target information outside the scope of the valid portion of the warrant. To the extent such search methods are used, the plain view exception is not available. As the record is currently constituted, there is little indication as to whether the forensic examiner’s search was even directed – much less properly limited – to those files that would substantiate a registration violation. The district court held that the redacted warrant authorized the forensic examiner to open and seize any image file because digital pictures “would be relevant to whether it was actually defendant who was using an unregistered user name or an e-mail account.” The district court’s speculation as to the probative value of the digital pictures is unsupported by the record developed below and appears somewhat strained, given that officers had determined, before even seeking the warrant, that Galpin’s I.P. address was the source of the “Medic Guy” posting and the photograph of Galpin found on the child’s MySpace page. The record indicates, moreover, that the investigator opened and played video image files in order to determine whether they contained sexual content. Nothing in the record is indicative of any possible evidentiary connection between the content of video files and the possession of an unregistered internet service provider account, internet communication identifier, or email address. On remand, the district court must determine whether a search limited to evidence of a registration violation would have necessitated the opening of image files or the playing of video files.

It’s hard to know exactly what to make of this language. But if we take it seriously, the Second Circuit appears to be saying that there is some sort of heightened standard for when an agent is allowed to conduct a search through a computer. Some of the words suggest at least a subjective test (thus the focus on whether the “search was even directed” at the evidence), which is what the Tenth Circuit adopted in United States v. Carey, 172 F.3d 1268, 1273 (10th Cir. 1999). Other parts of the passage suggest some sort of heightened scrutiny beyond subjective intent. Parts suggest a necessity test: Would a proper search have “necessitated” the opening of a particular file? And other parts of the passage suggest a “possible evidentiary connection” test, which I gather would be ess strict than a necessity test. But both tests would be really murky: What does it mean to say that a particular search query is “necessary”? And how possible is possible enough? Anyway, it’s hard to know exactly what the Second Circuit has in mind, and I suppose it is only dicta anyway. Still, the language seemed noteworthy in light of the lower court confusion about how to apply the plain view exception in digital search cases.