The 6th U.S. Circuit Court of Appeals ruled Monday that the government must have a search warrant before it can secretly seize and search stored e-mails. People that use e-mail as a form of communication have a reasonable expectation of privacy. Although surveillance of in-transit e-mails is prohibited, the government has been using the Stored Communications Act (SCA) to search stored e-mails without having to use a warrant. This week the appeals court found that the act violated the Fourth Amendment of the Constitution.

"It goes without saying that like the telephone earlier in our history, e-mail is an ever-increasing mode of private communication, and protecting shared communications through this medium is as important to Fourth Amendment principles today as protecting telephone conversations has been in past," the appeals court said.

Steven Warshak, owner and president of Berkeley Premium Nutraceuticals, brought the case against the government to stop investigators from searching his stored e-mails using the SCA. The district court ruled in favor of Warshak, and the government appealed the ruling to the 6th Circuit, where they were ultimately defeated.

Warshak is in the middle of a fraud investigation. He has pleaded not guilty to charges that he and his business defrauded customers and banks out of at least $100 million in a scheme where they billed credit cards without authorization.