United States v. Kelley and Probable Cause for Search Warrants:
Yesterday the Ninth Circuit published a Fourth Amendment decision that included a rather strongly worded dissent by Judge Sidney Thomas. In his dissent, Judge Thomas accused the majority (Judge Rymer and Ret'd Justice O'Connor) of "eroding" the Fourth Amendment by "lowering" the probable cause standard to fight the "scourge" of child pornography:
Child pornography is a scourge on our nation. But every hour, millions of unsolicited and deceptively disguised emails are sent to innocent computer users. Lowering our standards of probable cause to permit government intrusion into private residences based solely on proof of mere transmittal of unsolicited email constitutes an unwarranted erosion of the Fourth Amendment.
  So you're wondering, was the Fourth Amendment really eroded by the majority's decision? The answer is "no," although for a different reason than the majority offers. The reason Judge Thomas is wrong is that everyone in the case was applying the wrong legal standard, and the standard they applied was far more pro-defendant than it should have been. Had the judges applied the correct Fourth Amendment standard the case would have been a pretty obvious win for the government.

  The case is United States v. Kelley, and involves charges for knowingly receiving images of child pornography. The government obtained a search warrant for the contents of Kelley's AOL e-mail account after an investigation in Germany revealed that Kelley's account was on the recipient list of a number of e-mails containing child pornography. The question in the case was whether the affidavit in support of the warrant for Kelley's account made the case for probable cause under the Fourth Amendment.

  The critical part of the case comes at the beginning of the analysis section, in the middle of page 7:
Kelley and the government agree that unwitting receipt of e-mail containing contraband will not support probable cause. See 18 U.S.C. ยง 2252A(a)(2) (criminalizing the knowing receipt of child pornography); United States v. Romm, 455 F.3d 990, 998 (9th Cir. 2006) (holding that a person receives child pornography if he seeks it out). The dispute centers on whether the affidavit is sufficient even though it lacks direct evidence that Kelley actually solicited the offending attachments.
  In other words, the parties agreed that the warrant was valid only if the affidavit showed probable cause that Kelley knowingly received the images, not just that the images were there in the account. As a result, both the majority and dissenting opinions focus on whether the affidavit offered sufficient evidence that Kelley was a knowing recipient of the images rather than someone who was being "spammed" with the e-mails without knowing about it or against his will. The majority says that there was enough evidence to conclude that Kelley had asked to be a recipient of the e-mails; Judge Thomas concludes that there was a good chance that Kelley was an unwilling recipient and therefore that the warrant was invalid.

  But something seems off-track here: the court is applying the wrong Fourth Amendment standard. Search warrants don't require probable cause that a particular person committed a particular offense. Rather, they require probable cause that evidence or contraband is located in the place to be searched. The key case is Zurcher v. Stanford Daily, where the Court offered the following analysis:
  The critical element in a reasonable search is not that the owner of the property is suspected of crime, but that there is reasonable cause to believe that the specific "things" to be searched for and seized are located on the property to which entry is sought. . . . Federal Rule Crim.Proc. 41, which reflects "[t]he Fourth Amendment's policy against unreasonable searches and seizures," United States v. Ventresca, 380 U.S. 102, 105 n. 1 (1965), authorizes warrants to search for contraband, fruits or instrumentalities of crime, or "any . . property that constitutes evidence of the commission of a criminal offense. . . ." Upon proper showing, the warrant is to issue "identifying the property and naming or describing the person or place to be searched." Probable cause for the warrant must be presented, but there is nothing in the Rule indicating that the officers must be entitled to arrest the owner of the "place" to be searched before a search warrant may issue and the "property" may be searched for and seized. . . .
  The Court of Appeals for the Sixth Circuit expressed the correct view of Rule 41 and of the Fourth Amendment when, contrary to the decisions of the Court of Appeals and the District Court in the present litigation, it ruled that, "[o]nce it is established that probable cause exists to believe a federal crime has been committed, a warrant may issue for the search of any property which the magistrate has probable cause to believe may be the place of concealment of evidence of the crime." United States v. Manufacturers Nat. Bank of Detroit, 536 F.2d 699, 703 (1976).
  Against this background, it is untenable to conclude that property may not be searched unless its occupant is reasonably suspected of crime and is subject to arrest. And if those considered free of criminal involvement may nevertheless be searched or inspected under civil statutes, it is difficult to understand why the Fourth Amendment would prevent entry onto their property to recover evidence of a crime not committed by them, but by others. As we understand the structure and language of the Fourth Amendment and our cases expounding it, valid warrants to search property may be issued when it is satisfactorily demonstrated to the magistrate that fruits, instrumentalities, or evidence of crime is located on the premises.
  So the proper Fourth Amendment question was whether probable cause existed to believe child pornography was in the account, not whether there was probable cause that Kelley in particular was guilty of an offense.

  It seems that the government improperly failed to make this argument, so I suppose you can't fault the majority for applying the incorrect standard the government wrongly believed applied. (It's unclear whether the government also conceded Fourth Amendment protection in the e-mail in the first place, which would be front-page news if true.) At the same time, I think it does suggest that Judge Thomas's dissent is pretty far off-base. Judge Thomas decries the erosion of the Fourth Amendment under the wrong test, and under the right test his distinction between spam and invited e-mail is irrelevant.

  Thanks to How Appealing for the link to the opinion.