A Senate committee today backed sweeping privacy protections requiring the government, for the first time, to get a probable-cause warrant to obtain e-mail and other content stored in the cloud.

The Senate Judiciary Committee approved the package on a voice vote after about 30 minutes of debate, and sent the measure to the Senate floor, where it faces an uncertain future.

The legislation, (.pdf) sponsored by Sen. Patrick Leahy (D-Vermont), the committee's chair, and Michael S. Lee (R-Utah) nullifies a provision of federal law allowing the authorities to acquire a suspect's e-mail or other stored content from an internet service provider without showing probable cause that a crime was committed if the content is 180 days or older.

Under the current law, the 1986 Electronic Communications Privacy Act, the government can obtain e-mail without a warrant as long as the data has been stored on a third-party server – the cloud – for 180 days or more. The government only needs to show, often via an administrative subpoena, that it has "reasonable grounds to believe" the information would be useful to an investigation.

Initially, ECPA provided privacy to users, but that privacy protection eroded as technology advanced and people began storing e-mail and documents on servers for longer periods, sometimes indefinitely. The act was adopted at a time when e-mail wasn't stored on servers for a long time, but instead was held briefly on its way to the recipient's inbox. E-mail more than 6 months old was assumed abandoned.

"I think Americans are very concerned about unwarranted intrusions into our cyber lives," Leahy said ahead of the vote.

The bill enjoys backing from a wide range of lobbying interests, from the American Civil Liberties Union to the U.S. Chamber of Commerce.

The Judiciary Committee approved a nearly identical version of the bill in November. But it died a quiet death and, in Washington fashion, mutated into a package granting the public the right to automatically display on their Facebook feeds what they're watching on Netflix.

What the President Barack Obama administration thinks of the measure is a mixed bag. The Justice Department testified in March at House committee that the 180-day rule "no longer made sense." (.pdf)

But that doesn't mean the agency is on board with the change.

"The harder question is how to update those outdated rules and the statute in light of new and changing technologies while maintaining protections for privacy and adequately providing for public safety and other law enforcement imperatives," said Elana Tyrangiel, an acting assistant attorney general.

And on Thursday, Mary Jo White, the Securities and Exchange Commission's new chair, wrote the Senate Judiciary Committee that the bill's passage would hinder the government's "ability to protect investors."

Sen. Jeff Sessions (R-Alabama) said Thursday that federal authorities may simply abandon terrorism cases if they have to spent time comporting with the Fourth Amendment.

"Terrorism cases," he said during the committee hearing, "may never be followed up on just because of that burden."

The measure allows the authorities to bypass the warrant requirement for national security issues and emergencies. It also demands that the targets of warrants be immediately notified about the warrant.