Although this text applies to U.S, I've heard that the German Govt too is tightening it's grip on all activities.
On July 11, 2008, Steven Warshak, the president of a nutrition supplement company, learned the hard way (pdf) about the dangers of using web-based email. On May 6, 2005, the government got such an order for the contents of his emails.
Generally, the internet service provider (ISP) is required to give the subscriber notice of the subpoena, but the statute allows a delay of up to 90 days if the government just asks for the data and the court finds that "there is reason to believe that notification of the existence of the court order may have an adverse result", like endangering the life or physical safety of an individual, flight from prosecution, destruction of or tampering with evidence, intimidation of potential witnesses, or otherwise seriously jeopardizing an investigation or unduly delaying a trial. Using this provision the government got an order allowing it to delay telling Warshak of its access for 90 days, until early July 2006.
July came and went, as did August, September, October, November, December, January, February, March, April and May of 2007 before the government finally got around to telling Warshak that it had been reading his mail.
Warshak, like many others, used web-based or third-party provided email services like Yahoo! mail and NuVox communications. Thus, his inbox and outbox were literally out of his hands. If Warshak had used an internal email service that he controlled and the government wanted to get access to the contents of his email, they would have had to do it the old-fashioned way: Obtain a search warrant supported by probable cause, issued by a neutral and detached magistrate, specifying the place to be searched and the items to be seized. In fact, those are the precise words of the Fourth Amendment.