Facebook, Twitter and Google told Congress on Tuesday they were committed to cracking down on fake news operations on their platforms like the ones Russians conducted to meddle in last year's US presidential elections.
A day after bombshell indictments in a US probe of Moscow's election interference and possible coordination between President Donald Trump's campaign and Russia, Facebook, the three American internet giants sought to assure concerned lawmakers that they were taking necessary steps to rid their platforms of disinformation, propaganda and provocation.
In their testimony, the social media companies revealed startling new data showing many more millions of Americans were exposed to the fake news than previously thought. The new information gives the broadest picture yet of the Russian effort to spread discord across US society (See: Facebook, Twitter, Google reveal big-time Russian meddling in US polls).
Exasperated US senators harshly criticised representatives of Facebook, Twitter and Google at the hearing on Tuesday for not doing more to prevent Russian agents interfering with the American political process as early as 2015.
But according to media including The New York Times, while the tech executives were contrite about the Russian election meddling, they made few actual promises on Capitol Hill.
At one point, Sen Al Franken shook his head after he couldn't get all the companies to commit to not accepting political ads bought with North Korean currency.
The hearing by a subcommittee of the Senate Judiciary panel was moved last week into a cavernous hearing room usually reserved for high-profile events like Supreme Court confirmations. About 50 people waited to get in as senators fired pointed questions and waved at cardboard displays of outrageous ads.
''People are buying ads on your platform with rubles. They are political ads,'' Franken fumed. ''You put billions of data points together all the time ... Google has all knowledge that man has ever developed. You can't put together roubles with a political ad and go like, 'Hmmm, those data points spell out something pretty bad?' ''
Technology company representatives fumbled at points. After Franken pointed out foreign spending on US political campaigns is illegal, Google's director of law enforcement and information security, Richard Salgado, replied only that the search giant would refuse political ads paid with foreign currency ''if it's a good enough signal on illegality''.
''In hindsight, we should have had a broader lens,'' said Facebook's general counsel Colin Stretch.
The companies all pledged to do more and politely said they understood the seriousness with which lawmakers are taking the question of Russian meddling.
Sen Amy Klobuchar pressured the representatives to support her ''Honest Ads'' bill, which she is co-sponsoring with Sen Mark Warner and Sen John McCain, and which would bring political ad rules from TV, radio and print to the internet.
She dismissed pledges from the companies this week to be more transparent about political ads as an unenforceable ''patchwork'' of self-policing.
''We're not waiting for legislation,'' said Stretch, before Klobuchar cut him off and repeated her demand for a yes or no answer.
''We stand ready to work with you and your co-sponsors on that legislation going forward,'' Stretch replied, echoed by Twitter's and Google's representatives.
The hearing the first of three this week in which the three tech giants face a public grilling comes amid the increasing pace of investigations into the Trump administration's possible link to Russia.
Court papers unsealed on Monday revealed an indictment against President Donald Trump's former campaign chairman, Paul Manafort, and a guilty plea by another adviser, who admitted to lying to the FBI about meetings with Russian intermediaries.
Just five of the full committee's 11 Republicans attended the Senate subcommittee hearing, while all nine Democrats showed up.
On Wednesday, representatives of all three companies face hearings by the House and Senate intelligence committees.
In preparation for Tuesday's hearing, Facebook disclosed that content generated by Russia's infamous troll farm, the Internet Research Agency, potentially reached as many as 126 million users.
The company said IRA-linked accounts generated 80,000 posts on 120 pages between January 2015 and August 2017. Possible views reached the millions after people liked the posts and shared them.
Facebook had earlier turned over more than 3,000 advertisements linked to the agency. The ads, many of which focused on divisive social issues like immigration and gay rights, pointed people to the agency's pages, where they could then like or share its material.
Twitter said it uncovered and shut down 2,752 accounts linked to the IRA, nearly 14 times as many as it handed over to congressional committees three weeks ago.
The Russia-linked accounts put out 1.4 million election-related tweets from September through 15 November last year nearly half of them automated. The company also found nine Russian accounts that bought ads, most of which came from the state - backed news service RT, previously known as Russia Today.
And Google said it found evidence of ''limited'' misuse of its services by the Russian group, as well as some YouTube channels that were likely backed by Russian agents.
Google said two accounts linked to the Russian group spent $4,700 on ads on its platforms during the 2016 election.
The company also found 18 YouTube channels likely backed by Russian agents. Those channels hosted 1,108 videos with 43 hours of material, although they racked up just 309,000 views in the U.S. between June 2015 and November 2016, Google said.
Sen Richard Blumenthal revealed some of the ads taken out by Russians, including one that showed comedian Aziz Ansari holding up a sign that said ''Save time, avoid the line, vote from home,'' a message that falsely suggested voters could cast ballots by text message.
Another Twitter post urged voters to text ''Hillary'' to 59925 to cast their vote.
Blumenthal pressed Twitter's acting general counsel Sean Edgett to commit to researching how many voters may have been misled into incorrectly believing they had voted because of the posts.