Cloud computing lets Feds read your email
You have 'no expectation of privacy'
Thus, in the case of email messages stored and sent in the cloud, the government doesn't need a warrant, doesn't need probable cause, and doesn't need to provide the "owner" of the communications with notice. At least, not right away. Indeed, the government can request that the ISP "preserve" future communications that haven't even been conceived of yet, so that the government may demand them if the situation warrants.
Contrast this procedure with that required by both the US Constitution and the rules implementing them. If the mail was, for example, stored not by an ISP, but rather on Warshak's own internal mail server (and putting aside subpoenas to the recipients of the emails), the government would need a warrant, supported by probable cause - not just "reasonable grounds to believe" - with an oath or affirmation to a neutral magistrate. Under the Fourth Amendment, the warrant would have to specify exactly what was to be searched for and seized, and the evidence seized would have to be supported by probable cause. The warrant would have to be narrowly tailored to seize only the evidence for which there was probable cause, and could not be what the law calls a "general warrant". Finally, the government would have to prepare an inventory of whatever was seized, and give a copy of the warrant and a receipt to the suspect.
Thus, as a general rule, if the cops take stuff from you with a warrant, you know it, and you know when and what they took. The law does permit the judge to delay notice.
So Warshak challenged the constitutionality of the Stored Communications Act, trying to get a court order preventing the government from further seizing his emails without an actual warrant with notice and everything. Just as if his mail was, well, his mail, and not simply some file residing in a server at Yahoo or NuVox. The trial court ruled that Warshak was right, and issued the injunction finding that the search without notice or probable cause violated the Fourth Amendment, that the government's refusal to say that it wouldn't do it to Warshak again, coupled with the fact that the government had a policy of getting these orders without search warrants meant that there was at least a likelihood that Warshak's privacy could be violated in the future.
The Court of Appeals agreed, at least initially.
Meanwhile the government used the NuVox emails at Warshak's criminal trial. When Warshak complained that they had been obtained in violation of the Constitution, the trial court held even if the statute was unconstitutional - and allowed for illegal searches and seizures - because the cops reasonably relied on it the seizure of the emails was OK. The court went on to say that because it was Warshak's emails that were seized, none of Warshak's co-defendants could complain even if the search was illegal.
That still left the original court order preventing the government from seizing Warshak's emails in the future. Last week the Court of Appeals reconsidered its original decision, and found that the issue was - much like a salmonella tomato - not "ripe". You see, now that Warshak was in jail, there was little chance that the government would want to read his email, or indeed that he would have access to email. Thus, the court found that even if the process was patently unconstitutional, you couldn't prevent it from happening because you can't prove they are going to take it in the future - and you cant do anything about it afterwards because the government can rely on a statute authorizing illegal conduct. Warshak's only recourse now would be to sue the FBI agents that subpoenaed his email, or his ISP.