For years law enforcement used court orders to obtain the emails of suspects. Court orders are much simpler to get than an actual warrant. Well that practice is coming to an end:

The government must obtain a court warrant to require internet service providers to turn over stored e-mail to the authorities, a federal appeals court ruled Tuesday.

The decision by the 6th U.S. Circuit Court of Appeals was the first time an appellate court said Americans had that Fourth Amendment protection.

“The government may not compel a commercial ISP to turn over the contents of a subscriber’s e-mails without first obtaining a warrant based on probable cause” (.pdf), the appeals court ruled. The decision — one stop short of the Supreme Court — covers Kentucky, Michigan, Ohio and Tennessee

My favorite part of the decision:

“The Fourth Amendment must keep pace with the inexorable march of technological progress, or its guarantees will wither and perish,” the court ruled.

Unless you are George Bush.