The U.S. Congress would endanger the nation's security by passing even watered-down legislation to limit the National Security Agency's bulk collection of domestic phone records, several U.S. senators said Thursday.

Several members of the Senate Intelligence Committee voiced opposition to the USA Freedom Act, a bill aimed at reining in NSA bulk collection of telephone and other records, even though many civil liberties groups and technology companies have questioned whether the bill would work as its sponsors originally envisioned.

With the USA Freedom Act, Congress is "compromising to please a skeptical and frequently misinformed public" that's mistakenly worried about NSA surveillance, Senator Dan Coats, an Indiana Republican, said during a hearing on the House bill, taking place one year after the first leaks from former NSA contractor Edward Snowden were published.

The USA Freedom Act would ban what the NSA and the U.S. Department of Justice consider "bulk" collection of phone and business records, said James Cole, deputy attorney general at the DOJ. But Cole parsed the definition of "bulk" collection.

Quoting a House Intelligence Committee report on the USA Freedom Act, Cole said, "Bulk collection means indiscriminate acquisition. It does not mean the acquisition of a large number of communication records." Therefore, the House bill would allow the NSA collection of large numbers of records, if that collection were approved by the U.S. surveillance court.

An amended definition of what records the bill allows the NSA to collect gives the agency wide latitude, said Senator Mark Udall, a Colorado Democrat. The version of the USA Freedom Act that passed the House "is not the true reform I've demanded, and many other Americans have demanded, for years," he said.

The House bill is "vague enough to still allow the collection of mass information," Udall said. "The NSA has shown time and time again it will seize on any wiggle room in the law, and there's plenty of that in this bill."

The NSA phone records program helps protect national security, several senators argued, even though critics have found that many of the examples of investigations given to justify the program have only a limited connection to it.

Nevertheless, the Senate should "step back" and reconsider whether to pass the USA Freedom Act, said Senator Saxby Chambliss, a Georgia Republican.

"It seems to me this bill is fixing a lot of things that simply aren't broken," Chambliss said. "My name is in [the NSA database] along with everybody else's. But frankly, I'm not worried because I don't talk to terrorists."

The House of Representatives passed a watered-down version of the USA Freedom Act, approved by Obama's administration, in May despite concerns from privacy advocates that it would allow the NSA to continue to collect business records under broad categories.

The CEOs of Apple, Facebook, Google, Microsoft, Twitter and other tech companies urged senators to narrow the definition of records the NSA could search.

"Unfortunately, the version that just passed the House of Representatives could permit bulk collection of Internet 'metadata,' something that the Administration and Congress said they intended to end," the tech CEOs said in a letter to senators Thursday.

Several former backers of the USA Freedom Act, including some of its original sponsors, withdrew their support for the bill after lawmakers made changes to it, advocated by the Obama administration, in the week leading up to the May 22 House vote.

A major change to the bill before the House vote was an expanded definition of a 'specific selection term" that the NSA must use to target its searches. The amended version of the bill allows the NSA to target things such as a "person, entity, accounts, address, or device," instead of, in the original language, a "person, entity, or account."

The words "address" and "device" in the new language, as well as the open-ended term "such as," would allow the NSA to target wide groups of people, critics have said. The new version of the bill would allow the NSA to target an entire state, an entire phone network or an entire email provider, Harley Geiger, senior counsel for the Center for Democracy and Technology, told senators.

Still, several members of the intelligence committee, Republicans and Democrats, questioned the need for even the watered-down bill.

Leaks by Snowden have led to the "continual demonization" of the NSA, said Senator Barbara Mikulski, a Democrat from Maryland, where the NSA is headquartered. People working at the NSA "keep America safe," she said.

Senator John "Jay" Rockefeller, a West Virginia Democrat, called the proposed NSA reform "unnecessary and unpredictable." The USA Freedom Act "might make the public feel better," but would hurt national security. he said.

The NSA has trained people watching over the data the agency collects, while the House bill would create a new program that has the telecom carriers holding onto the phone records, he said.

"The public's never going to trust us, but if we're doing something for national security, which is trustworthy, by trustworthy people who are trained ... why cash it out?" Rockefeller said. "Nobody has complained about privacy violations. Everybody's worried about what might happen."

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's email address is grant_gross@idg.com.