A Senate committee on Thursday unanimously backed sweeping digital 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 measure, sponsored by Sen. Patrick Leahy (D-Vermont), the head of the Senate Judiciary Committee, amends the 1986 Electronic Communications Privacy Act. The amendment would nullify a provision that allows the government 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.

The development comes as e-mail privacy is again in the spotlight after FBI investigators uncovered an affair between then-CIA chief David Petraeus and his biographer Paula Broadwell after gaining access to e-mail accounts used by Broadwell.

Currently, the government can obtain e-mail without a warrant as long as the content has been stored on a third-party server for 180 days or more, and only needs to show, often via an administrative subpoena, that it has "reasonable grounds to believe" the information would be useful in an investigation.

The measure and its minor amendments still face tough fights before the full Senate and in the House, and it likely will be revised to comport with concerns from the Justice Department and other lawmakers that the bill is soft on crime. The measure is not expected to reach the Senate floor until sometime next year.

"There will still be work to be done on this," Leahy said when the 50-minute Judiciary Committee hearing ended Thursday.

Leahy noted that the measure leaves intact "federal counterterrorism" provisions such as the Patriot Act, which gives the FBI power to acquire phone, banking and other records using a so-called "national security letter" without court warrants.

Sen. Chuck Grassley (R-Iowa) agreed that the ECPA amendment likely will be revised. "I think it's a start of an important discussion," he said.

When enacted, ECPA provided privacy to users, but that privacy protection became eroded as technology advanced and people began storing e-mail 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.

Despite the reform's uncertain future, the American Civil Liberties Union applauded the committee's Thursday action.

"This is an important gain for privacy. We are very happy that the committee voted that all electronic content like emails, photos and other communications held by companies like Google and Facebook should be protected with a search warrant," said Chris Calabrese, the ACLU's legislative counsel. "We believe law enforcement should use the same standard to search your inbox that they do to search your home."

In a bid to get his measure through, Leahy attached his privacy measure to a package that amends the Video Privacy Protection Act and which has broad support from lawmakers.

The video act outlaws the disclosure of video rentals unless the consumer gives consent, on a rental-by-rental basis. Congress adopted the measure in 1988 after failed Supreme Court nominee Robert Bork's video rental history was published by the Washington City Paper during confirmation hearings.

But the result of the act is that it prohibits Netflix customers from allowing their Facebook streams to automatically update with information about the movies they are watching, though Spotify and other online music-streaming customers can consent to the automatic publication on Facebook of the songs they're listening to.

The Judiciary Committee amendment allows Facebook users to have their timelines automatically updated with whatever they're watching on Netflix, allowing consumers to opt-in for two-year periods.

"The consumer should have the ability to opt in to that," said Sen. Dianne Feinstein (D-California.)

The House passed similar Netflix legislation last year.