The Sixth Circuit Court of Appeals has handed down a ruling that delights privacy advocates and Fourth Amendment purists: In U.S. v. Warshak, it found that the government should have obtained a search warrant before seizing and searching defendant Stephen Warshak’s emails, which were stored by email service providers.

In the criminal case, Warshak was being investigated by the Justice Department for fraud and related crimes associated with his marketing of “male enhancement” pills.

During the investigation, the Justice Department ordered the email provider to prospectively preserve copies of Warshak’s future emails, using a subpoena and a non-probable cause court order. The government based its actions on the Stored Communications Act, which allows it to obtain emails already in storage with a provider.

The Court of Appeals agreed that the government did act in good faith by relying on the Stored Communications Act. However, it continued, a warrant was in order.

“If we accept that an email is analogous to a letter or a phone call, it is manifest that agents of the government cannot compel a commercial ISP to turn over the contents of an email without triggering the Fourth Amendment,” the decision reads. “An ISP is the intermediary that makes email communication possible. Emails must pass through an ISP’s servers to reach their intended recipient. Thus, the ISP is the functional equivalent of a post office or a telephone company.”

via Technology News: Tech Law: Court Ruling Grants Email the Cloak of Privacy.