Top Democrats on the Senate Intelligence Committee berated lawyers for social media giants Facebook, Twitter and Google for a lethargic response to Russian interference in U.S. politics, as the companies’ lawyers faced a second day of grilling in Congress.

“Your first presentations were less than sufficient,” Mark Warner said at the panel’s hearing Wednesday, saying lawmakers were at first “blown off” by companies that in effect said, “Nothing like this happened. Nothing to see here,” only to later acknowledge that Russian efforts had reached perhaps as many as 150 million Americans.

Several senators chided the companies for sending their lawyers instead of their chief executive officers. “We would appreciate seeing the top people who are actually making the decisions,” said Sen. Angus King or Maine, an independent who caucuses with Democrats. The committee’s leaders have said they wanted witnesses able to answer technical questions, not necessarily the CEOs.

Still, Facebook’s General Counsel Colin Stretch was dressed down when he was unable to tell Warner whether his company had cross-checked 30,000 fake accounts it took down before the French election to see if any had been active in the U.S.

“I will have to come back to you on that, sir,” Stretch said.

“We’ve had this hearing scheduled for months,” Warner of Virginia replied. “I find your answer very, very disappointing.”

The morning hearing provided a rocky start to a long day for the companies, which appeared in the afternoon before the House Intelligence Committee. Members led by Warner are pushing for legislation that would require the companies to disclose the source of campaign ads, as old-line broadcasters have long been required to do.

The companies – which cultivate their influence in Washington through lobbying and campaign contributions – have long resisted federal regulation. Eric Schmidt, the chairman of Google’s parent, Alphabet Inc., told a conference in Washington Thursday that “we worry about premature regulation. I would be very, very careful about simple answers to these problems.”

The lawyers at the Senate hearing stopped short of endorsing the proposed campaign ad-disclosure legislation. Sean Edgett, Twitter’s acting general counsel, said his company supported the general idea but had some ideas for “fine-tuning.”

The questioning of the companies was even more pointed than at a Senate Judiciary subcommittee session Tuesday.

The confrontations on Capitol Hill failed to daunt Facebook and Alphabet investors. The companies’ shares climbed as their underlying strength and dominance in digital advertising outweighed any concerns about the probe. Facebook is projected to report record sales after markets close Wednesday, and its stock earlier reached an all-time intraday high. Shares of Twitter, whose business has been less stable, were little changed.

The intelligence committee focused not just on Russian-backed advertising but also on the extent to which unpaid posts and articles were used in an effort to manipulate American opinion and create division.

In the latest disclosure of manipulation of the social networks, Stretch testified Wednesday that 120,000 Russian-linked posts on Facebook’s Instagram application reached 16 million people starting in October 2016 and about 4 million before that. Facebook has said previously that about 170 Instagram accounts had been deleted. That’s in addition to the 126 million Facebook users the company previously disclosed saw 80,000 Russia-linked posts on Facebook from a single “troll farm.”

While Republican Sen. Richard Burr, the committee’s chairman, joined in chiding the social-media companies for failing to do more, he resisted Democratic assertions that Russian-linked ads may have been targeted to key states to help Donald Trump win the presidency.

“What you haven’t heard is almost five times more ads were directed at the state of Maryland,” a state that wasn’t in play in the election, than in Wisconsin, which was a key state in Trump’s victory, Burr said. He said only $300 was spent in Pennsylvania, a battleground state.

But Burr said Russia’s efforts were wide-ranging, and told the companies that if they need an antitrust waiver to work together, they should let the government know. His closing remarks laid out his views that efforts so far were just the beginning, with much more work needed to be done.

“Don’t let nation-states disrupt our future,” he said. “You’re the front line of defense for it. Please take that back to your companies.”

Warner said that paid Russian ads on social-media networks are only a small part of a campaign to manipulate U.S. opinion and undermine democracy through viral postings.

“These ads are just the tip of a very large iceberg,” he said. “The real story is the amount of misinformation and divisive content that was pushed for free on Russian-backed pages, which then spread widely on the news feeds of tens of millions of Americans.”

Sen. Dianne Feinstein of California, noting that she represents Silicon Valley, told the witnesses, “I must say I don’t think you get it” and that their “vague answers” aren’t sufficient. She said, “what we’re talking about is a cataclysmic change. What we’re talking about is cyberwarfare.”

At the hearing of a Senate judiciary subcommittee on Tuesday, attorneys for the companies were forced to acknowledge that they aren’t sure they’ve measured the full extent of foreign manipulation of their social networks and don’t yet have the technology to ensure it won’t happen again.

“We need to understand the behavior and we need to have the capacity both as a company and as an industry to be able to track it and eradicate it,” Stretch, the Facebook general counsel. He said the company will double its safety and security staff to 20,000, including contract workers, by the end of 2018 to help track foreign interference and extremist postings.

While some Republicans raised constitutional questions about any possible regulation of social-media content, Democrats on the panel said Congress must at least act on disclosure.

Republican Burr of North Carolina has said he was waiting to decide. As the hearing concluded, however, Burr said the companies are subject to the oversight by the Federal Election Commission and laws against buying political ads with foreign money.

Members of both parties showed examples of efforts by Russian-affiliated groups to sow discord in the U.S. through social media.

Burr showed ads that promoted bogus pro-Islamic and anti-Islamic demonstrations on the same day at the same time in Texas. Warner showed a bogus Christian group that ran a post of Democrat Hillary Clinton with horns.

Republican Sen. Susan Collins of Maine noted the Russians targeted her state’s governor, with groups both attacking and supporting his remarks, as recently as August of this year.

While the companies continued to pledge to do better to spot fakes and take down automated bots, senators indicated they weren’t satisfied. Warner said he was disappointed the companies couldn’t say if additional “troll farms” in Russia or affiliated with Russia may have also been operating and said the companies have a lot more work to do.

Bloomberg’s Bill Allison, David McLaughlin, Billy House and Terrence Dopp contributed.

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