The House of Representatives on Thursday passed legislation protecting US businesses and agencies from cyber-attacks, a measure that critics say erodes civil liberties by allowing firms to onpass private data.

The Republican-controlled chamber defied a veto threat by the White House to pass the Cyber Intelligence Sharing and Protection Act (CISPA) in a 248-162 vote.

Its fate is less assured in the Democratically controlled Senate, but supporters like House Intelligence Committee chairman Mike Rogers said it was vital to shore up computer systems woefully vulnerable to outside attack.

"We can't stand by and do nothing as US companies are hemorrhaging from the cyber-looting coming from nation states like China and Russia," Rogers said.

Reaction to the bill, which would allow private companies to exchange confidential personal information with the federal government, was mixed.

"Without question, the path to the House vote wasn't an easy one," said Dean Garfield, chief executive of the Information Technology Industry Council, a leading technology trade association.

"But, at the end of the day, we have legislation that would markedly improve our country's cyber defenses and enhance our citizens' safety."

CISPA is reportedly endorsed by Facebook and Microsoft as well as communication giants Verizon and AT&T.

But President Barack Obama's White House said the bill "lacks sufficient limitations on the sharing of personally identifiable information between private entities and does not contain adequate oversight or accountability measures necessary to ensure that the data is used only for appropriate purposes.

Texas Republican Joe Barton voted no because the bill "does not protect the privacy of the individual American citizen," and erosions of such civil liberties are "a greater threat to democracy and liberty than the cyber threat is to America."

Digital rights group Electronic Frontier Foundation said such "vaguely-worded cybersecurity bills" effectively allow companies to bypass existing law, spy on communications and pass sensitive personal data to the government.

"We will not stand idly by as the basic freedoms to read and speak online without the shadow of government surveillance are endangered by such overbroad legislative proposals," said Rainey Reitman, EFF Activism Director.

Members of the online "hacktivist" group took to Twitter to voice opposition to the bill.

"#CISPA has only passed the House. The fight is still on," Anonymous said on Twitter account @youranonnews.