The Senate Judiciary Committee voted overwhelmingly on Thursday to require police to obtain a warrant before reading people's emails, Facebook messages and other forms of electronic communication.
Sen. Patrick Leahy (D-Vt.), the author of the bill and chairman of the committee, said he does not expect the full Senate to vote on the measure until next year.
He called the committee vote an important step forward and said he plans to negotiate with the House to guide the bill to passage during the next Congress.
Chris Calabrese, legislative counsel for the American Civil Liberties Union, called the vote an "important gain for privacy."
“We believe law enforcement should use the same standard to search your inbox that they do to search your home,” he said in a statement.
Under the Electronic Communications Privacy Act (ECPA) of 1986, police only need a subpoena, issued without a judge's approval, to read emails that have been opened or that are more than 180 days old.
When lawmakers passed ECPA more than 25 years ago, they failed to anticipate that email providers would offer massive online storage. They assumed that if a person hadn't downloaded and deleted an email within six months, it could be considered abandoned and wouldn't require strict privacy protections.
"I believe strongly that we need to eliminate the anachronistic distinction made in the law depending upon whether the emails are more or less than 180 days old," Leahy said at Thursday's meeting.
Sen. Chuck Grassley (R-Iowa), the panel's ranking Republican, agreed to vote in favor of the bill, but he said it still needs more work before becoming law.
He criticized Leahy for crafting the legislation "behind closed doors" and expressed concern that the measure could impede critical police investigations.
He noted that the Obama administration has not yet taken a position on the bill, but he said Justice Department officials expressed concern to him that the measure could "negatively impact" civil cases.
Grassley offered an amendment that would allow police to avoid the warrant requirement if they are investigating crimes involving kidnapping, child pornography or violent crimes against women, including rape.
The committee Democrats argued that police can already bypass warrant requirements in exigent circumstances and said that Grassley's amendment would create an unnecessary carve-out based on the type of police investigation.
Sen. Mike Lee (R-Utah) joined the Democrats in rejecting Grassley's amendment.
Leahy's bill allows law enforcement to request a renewable 180 delay for notifying the subjects of investigations that their emails have been seized. Current law allows police to request 90-day delays.
The panel approve an amendment from Lee that reduced the available delay back to 90 days for civil investigations.
All of the committee members voted for the legislation except for Sen. Jeff Sessions (R-Ala.), who was not present but recorded a "no" vote.
The committee attached the email privacy legislation to H.R. 2471, a House bill that loosens video privacy requirements.
That bill, which cleared the House last year, would allow users of Facebook and other social media sites to opt in to automatically share which online videos they have watched.
Currently, Facebook users can choose to automatically reveal which songs they listen to and which articles they read. But the Video Privacy Protection Act bans the sharing of any video history information without written consent by the consumer or a warrant from the police.
The change in the video privacy law is Netflix's top lobbying priority in Washington.
Leahy said the legislation will allow consumers "if they wish, to share their movie and television watching experiences through social media, while also ensuring that the important privacy protections in this law are not diminished."
This story was updated at 1:11 p.m.