"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized." <a href="http://en.wikipedia.org/wiki/Fourth_Amendment_to_the_United_States_Constitution" rel="nofollow">http://en.wikipedia.org/wiki/Fourth_Amendment_to_the_United_...</a><p>"particularly describing the place to be searched, and the persons or things to be seized"<p>Clearly this is a violation of the 4th Amendment as such a key would give them the ability to conduct unfettered and "unparticular" searches. A more targeted, and constitutionally legal, approach would have been to order lavabit to use, but not disclose, the private key to decrypt specific emails from specific people. Given that the police know the public key, they could verify that lavabit had supplied correct decryptions.