In     an earlier post, co-blogger David Post pointed to     a state trial court ruling in Montana, for which he was an    expert for the defense, which concluded that the government    needs a warrant under the Fourth Amendment and/or the Montana    Constitution for a police officer to go undercover on Facebook    as a teenage girl, friend a target, and have conversations    with that target. Heres a different perspective on the case.    To the extent the judge was relying on the Montana    Constitution, the decision is plausible. On the other hand, the    decision is plainly wrong if it was relying on the federal    Fourth Amendment.  
    For purposes of the federal Fourth Amendment, the law is really    clear: You give up your Fourth Amendment rights in what you    knowingly disclose to another person such as an undercover    officer or informant. If you communicate with a person in a    Fourth Amendment protected space such as your home, you cant    claim a Fourth Amendment violation in what you shared with the    person if they violated your confidences and happen to be (or    are working with) law enforcement. See, e.g., United States v.    White, 401 U.S. 745 (1971); Hoffa v. United States, 385 U.S.    293 (1966); Lewis v. United States, 385 U.S. 206 (1966); Osborn    v. United States, 385 U.S. 323 (1966); Lopez v. United States,    373 U.S. 427 (1963); On Lee v. United States, 343 U.S. 747    (1952).  
    As I explained in a    forthcoming article, this legal rule was originally the    point of the subjective expectation of privacy test of    Katz, the thought being that you did not manifest    your privacy rights in what you disclosed to another even in    Fourth Amendment protected space. The Supreme Court later moved    the principle over to the objective expectation of privacy    test instead, where it announced the idea as the so-called    third-party doctrine: [T]he Fourth Amendment does not prohibit    the obtaining of information revealed to a third party and    conveyed by him to Government authorities, even if the    information is revealed on the assumption that it will be used    only for a limited purpose and the confidence placed in the    third party will not be betrayed. United States v. Miller, 425    U.S. 435, 443 (1976).  
    Those principles are directly applicable in the Montana    decision. The defendant, Windham, thought he was communicating    with a 16-year old girl named Tammy Andrews. It turned out    that Andrews was actually an adult police officer, proof that        on the Internet nobody knows youre a cop. The government    is trying to use what the officer saw as Tammy Andrews in    communication with Windham, which is only what Windham    knowingly reveled to Andrews. From a standpoint of the    federal Fourth Amendment, its a trivial case. Theres no    plausible argument for Fourth Amendment protection.  
    Importantly, though, that doesnt mean that the result is    wrong. It may just be correct as to the Montana Constitution    instead of the Fourth Amendment. State courts can interpret the    state constitution more broadly than the federal Fourth    Amendment And in State v. Goetz, 345 Mont. 421 (2008),    the Montana Supreme Court held that the state constitution    requires a warrant when an undercover agent wants to record a    one-on-one conversation with a target, even though the Fourth    Amendment doesnt require that. Under Goetz, theres    at least a plausible argument that either the use of the    undercover, or at least the recording of the communications,    required a warrant under the state constitution.  
    Its not a slam dunk, though, for two reasons. First, the focus    in Goetz seems to be the recording of the    communication without the targets consent. Facebook    communications are inherently recorded in the sense that this    is how Facebook works. In analogous contexts, some state courts    have held that a target consents to recording when they use    messaging services that necessarily record their messages.  
    Second, it might matter that the defendant in this case was in    Germany at the time these communications ensued. Assume theres    a requirement of a warrant under the Montana Constitution for    communications that occur inside Montana. If an undercover    officer in Montana has communications with a target in Germany,    does the Montana Constitution require the same warrant? Is the    search occurring in Germany for purposes of the state    constitution, and if so can a Montana court issue a warrant for    a search there? Or does the search occur in Montana for state    constitutional purposes because the recording occurred there?    Im not sure.  
    However a court should resolve these questions, though, this is    an argument only about the state constitution rather than the    Fourth Amendment. Under the Supremacy Clause, the ruling would    apply to state officers but not federal officers.  
    Finally, in the comment threads to Davids post, several    commenters raised the Computer Fraud and Abuse Act. If the    government thinks its a crime to violate Terms of Service on    Facebook, which was the DOJ position in the Lori Drew case, why    doesnt that forbid the governments procedure here as a matter    of federal law? I think there are three independent reasons.    First, an exception to the CFAA expressly exempts law    enforcement investigations, see 18 U.S.C. 1030(f), so this    wouldnt violate the CFAA even if you believe that TOS    violations generally violate the CFAA. Second, there is no    federal suppression remedy for statutory violations absent a    clear directive of Congress, of which there is none here. And    third, even though DOJ argued that the TOS violations in Drew    violated the CFAA, the DOJ was wrong, as the district court    recognized in tossing the convictions.  
      Orin Kerr is the Fred C. Stevenson Research Professor at The      George Washington University Law School, where he has taught      since 2001. He teaches and writes in the area of criminal      procedure and computer crime law.    
Read more here: 
Volokh Conspiracy: Undercover Facebook investigations and the federal/state divide  a response to David Post