Major tech companies, advocacy groups, and at least one senator have publicly proclaimed their opposition to two bills currently working their way through Congress. The two pieces of proposed legislation would each significantly expand use of National Security Letters to include "Electronic Communication Transactional Records"—better known as metadata.

As Ars has reported previously, federal investigators issue tens of thousands of NSLs each year to banks, ISPs, car dealers, insurance companies, doctors, and others in terrorism and espionage investigations. The letters demand personal information, and they don't need a judge's signature, much less a showing of probable cause. They also come with a default gag to the recipient that forbids the disclosure of the NSL to the public or the target.

On Thursday, the Senate Judiciary Committee is set to vote on one of those provisions as an amendment to a bill called the Electronic Communications Privacy Act Amendments Act of 2015 (S. 356). The provision would allow NSLs to target "account number, login history, length of service (including start date)… Internet Protocol address… routing, or transmission information…" and more.

This amendment is authored by Sen. John Cornyn (R-Texas), and it's being tacked on to a pending Senate bill. If passed, the Electronic Communications Privacy Act Amendments Act of 2015 would mandate a warrant for the government to access e-mail and data stored online. (The House unanimously passed its companion version, known as the Electronic Communications Privacy Act, in April 2016.)

The second possible legislative route to expanding NSL power comes via a revision to the Intelligence Authorization Act for Fiscal Year 2017.

In a letter sent to the Judiciary Committee on Monday, groups including the American Civil Liberties Union, Amnesty International, and the Electronic Frontier Foundation said they would withdraw their support for the badly needed ECPA reform bill if the Cornyn amendment or the revision to the IAA were allowed to stand.

As they wrote:

The civil liberties and human rights concerns associated with such an expansion are compounded by the government’s history of abusing NSL authorities. In the past ten years, the FBI has issued over 300,000 NSLs, a vast majority of which included gag orders that prevented companies from disclosing that they received a request for information. An audit by the Office of the Inspector General (IG) at the Department of Justice in 2007 found that the FBI illegally used NSLs to collect information that was not permitted by the NSL statutes. In addition, the IG found that data collected pursuant to NSLs was stored indefinitely, used to gain access to private information in cases that were not relevant to an FBI investigation, and that NSLs were used to conduct bulk collection of tens of thousands of records at a time.

For his part, Sen. Ron Wyden (D-Ore), a longstanding civil liberties-minded lawmaker, also voiced his opposition to this amendment in a statement sent to Ars.

"This bill takes a hatchet to important protections for Americans’ liberty," Wyden said, speaking specifically of the IAA. "This bill would mean more government surveillance of Americans, less due process, and less independent oversight of US intelligence agencies."