After a closed-door briefing of the House of Representatives, lawmakers call for a review of the Patriot Act

Anger was mounting in Congress on Tuesday night as politicians, briefed for the first time after revelations about the government's surveillance dragnet, vowed to rein in a system that one said amounted to "spying on Americans".

Intelligence chiefs and FBI officials had hoped that the closed-door briefing with a full meeting of the House of Representatives would help reassure members about the widespread collection of US phone records revealed by the Guardian.

But senior figures from both parties emerged from the meeting alarmed at the extent of a surveillance program that many claimed never to have heard of until whistleblower Edward Snowden leaked a series of top-secret documents.

The congressional fury came at the end of a day of fast-moving developments.

• In a lawsuit filed in New York, the American Civil Liberties Union accused the US government of a process that was "akin to snatching every American's address book".

• On Capitol Hill, a group of US senators introduced a bill aimed at forcing the US federal government to disclose the opinions of a secretive surveillance court that determines the scope of the eavesdropping on Americans' phone records and internet communications.

• A leading member of the Senate intelligence committee, Ron Wyden, came close to saying that James Clapper, the US director of national intelligence, misled him on the scope of government surveillance during a March hearing. Clapper admitted earlier this week that he gave the "least untruthful" answer possible to a question by Wyden.

• Chuck Hagel, the defense secretary, said he ordered a wide-ranging review of the Defense Department's reliance on private contractors. Snowden had top-security clearance for his work at Booz Allen Hamilton, an NSA contractor. Booz Allen issued a statement on Tuesday saying that Snowden had been fired for "violations of the firm's code of ethics".

• In Brussels, the European commission's vice-president, Viviane Reding, sent a letter demanding answers to seven detailed questions to the US attorney general, Eric Holder, about Prism and other American data snooping efforts.

• Snowden was at an undisclosed location after he checked out of a Hong Kong hotel on Monday. The director of Human Rights Watch, Peter Bouckaert, said Snowden should not consider himself safe in Hong Kong.

Newspapers in Hong Kong feature the NSA leaker Edward Snowden. Photograph: Bobby Yip/Reuters

After the congressional briefing, Xavier Becerra, leader of the House minority caucus, said there had not been enough oversight of government surveillance programs. "We are now glimpsing the damage," he said, referring to failures to repeal aspects of the Patriot Act sooner. "It was an extraordinary measure for an extraordinary time but it shouldn't have been extended."

Others said the White House and intelligence committee leaders had been misleading when they claimed all members of Congress were briefed about the mass swoop of telephone records.

"There was a letter that we were supposed to have received in 2011 but I can't find it and most of my friends in Congress did not receive this either," said New Jersey Democrat Bill Pascrell, who claimed the widespread collection of phone data amounted to "spying on Americans … This is one of the first briefings I have been to where I actually learned something."

The anger was apparent in both parties. The conservative Republican Steve King of Iowa predicted joint action from Congress would be imminent. "There is going to be a bipartisan response to this," he said.

Pascrell said: "There were no Democrats or Republicans in there at all, which is a healthy sign, it means we can get something done about this."

Another Republican, Tom McClintock of California, claimed the phone snooping amounted to an abuse of fourth amendment rights. "Going back to the days of British rule we have sought to stop the authorities barging in on people's privacy just in case they found something," he said. "The fourth amendment was passed to make sure that never happened and it is time to make sure it does not ever happen again."

Elijah Cummings, another Democrat unhappy at the Obama administration's security practices, came out of the secret briefing saying: "We learned a lot [but] I'm not comfortable."

Pascrell said: "People should know what's going on in their name but we need to start with Congress knowing what the heck is going on."

Earlier the Republican House Speaker, John Boehner, called Snowden – the 29-year-old former intelligence contractor who revealed the extend of the surveillance efforts – a traitor. But as attention switched from the leaker to the issues raised by his actions now looks increasingly certain that Congress will take steps to try to rein in the power of the intelligence services.

Google and Facebook demand transparency

US authorities faced challenges on other fronts: Google's chief legal counsel wrote to the Justice Department to request the ability to detail its co-operation with the government on surveillance orders, in the hope of assuring customers that it does not turn over user data wholesale to the NSA.

"Google's numbers would clearly show that our compliance with these requests falls far short of the claims being made," wrote Google's David Drummond. "Google has nothing to hide."

Facebook's general counsel, Ted Ullyot, issued a similar statement, saying the company "would welcome the opportunity to provide a transparency report that allows us to share with those who use Facebook around the world a complete picture of the government requests we receive, and how we respond".

A new coalition of privacy groups, internet companies and activists, called Stop Watching Us, unveiled itself Tuesday to demand "the US Congress reveal the full extent of the NSA's spying programs," which amount to "a stunning abuse of our basic rights." The coalition includes Mozilla, Reddit, John Cusack and the ACLU, among others.

The NSA affair continued to have international ramifications. In the European commission letter, Reding warns Holder that "given the gravity of the situation and the serious concerns expressed in public opinion on this side of the Atlantic" she expects detailed answers before they meet at an EU-US justice ministers' meeting in Dublin on Friday.

In the letter, released to the Guardian, Reding detailed her serious concerns that the Americans are "accessing and processing, on a large scale, the data of EU citizens using major US online service providers". She said that programs such as Prism, and the laws that authorise them, could have "grave adverse consequences for the fundamental rights of EU citizens".

She also warns Holder that the nature of the American response could affect the whole transatlantic relationship.

• This article was amended on 28 June 2013 to remove an incorrect reference to Hong Kong as a "Chinese province".