Last year, Grassley expressed concern that the bill could hinder law enforcement, but he agreed to move it out of committee. The bill never received a vote on the Senate floor.
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.
Sen. Mike Lee (R-Utah), a co-sponsor of the bill, agreed with Leahy that ECPA is out of date.
"In the nearly three decades since ECPA became law, technology has advanced rapidly," Lee said at Thursday's meeting. "The prevalence of email and the low cost of electronic data storage have made what were once robust protections insufficient to ensure that citizens’ Fourth Amendment rights are adequately protected."
The three senators all said they were troubled by recent revelations that the Internal Revenue Service believed it did not need a warrant to access emails in many cases.