DustyShadow writes "In the case In re United States, Judge Mosman ruled that there is no constitutional requirement of notice to the account holder because the Fourth Amendment does not apply to e-mails under the third-party doctrine. 'When a person uses the Internet, the user's actions are no longer in his or her physical home; in fact he or she is not truly acting in private space at all. The user is generally accessing the Internet with a network account and computer storage owned by an ISP like Comcast or NetZero. All materials stored online, whether they are e-mails or remotely stored documents, are physically stored on servers owned by an ISP. When we send an e-mail or instant message from the comfort of our own homes to a friend across town the message travels from our computer to computers owned by a third party, the ISP, before being delivered to the intended recipient. Thus 'private' information is actually being held by third-party private companies."" Updated 2:50 GMT by timothy: Orin Kerr, on whose blog post of yesterday this story was founded, has issued an important correction. He writes, at the above-linked Volokh Conspiracy, "In the course of re-reading the opinion to post it, I recognized that I was misreading a key part of the opinion. As I read it now, Judge Mosman does not conclude that e-mails are not protected by the Fourth Amendment. Rather, he assumes for the sake of argument that the e-mails are protected (see bottom of page 12), but then concludes that the third party context negates an argument for Fourth Amendment notice to the subscribers."