In U.S. v. Warshak, the Sixth Circuit recognized that email is equivalent to a letter or phone call for the purposes of the Fourth Amendment. Therefore, the government cannot force an internet service provider to turn over the contents of an email without abiding by judicial procedures laid out by the Fourth Amendment, such as a warrant granted based on probable cause. The Department of Justice has indicated some support for this view, but should clarify its official policy.
ECPA permits a governmental entity to force a service provider to disclose the contents of electronic communications in certain circumstances. Under the compelled-disclosure provisions, the government can obtain communications without a warrant if they are stored with a remote computing service or an electronic service provider for more than 180 days. These distinctions are outdated and inconsistent with the Fourth Amendment.
Congressman Sensenbrenner: “It's no secret that, in the digital age, privacy is harder to maintain, but Americans should not have to choose between technology and privacy. The Fourth Amendment protects us from unreasonable searches and seizures. In the Internet-era, this should apply to email and other forms of electronic communication because it is central to our daily lives. As Americans, we have a reasonable expectation of privacy. In order to execute a search, legal procedures must be followed. Obtaining emails without going through the proper judicial channels violates the Fourth Amendment. I am optimistic Congress will update ECPA and hope that Attorney General Holder will assure the American people their privacy is being protected by the DOJ.”
Letter to Attorney General Holder here.