Facebook and Twitter made a hotly anticipated appearance on Capitol Hill today, as top executives sat for a day’s worth of questions from lawmakers related to election interference, political bias, and more.

In the day’s first hearing, Twitter CEO Jack Dorsey shared the dais with Facebook’s chief operating officer, Sheryl Sandberg, for questions related to how the companies are protecting their platforms from abuse. (Google declined to send its CEO, and was represented by an empty chair.)

In the day’s second hearing, Dorsey alone faced more four hours of questions from members of the House Energy and Commerce Committee. Members of Congress asked mostly well informed questions about a wide range of subjects, and the tone was generally cordial.

Here were the day’s biggest moments.

Google wasn’t there, and senators were angry

Today’s Senate hearing was aimed at getting top Silicon Valley leadership to testify before Congress. Twitter sent its CEO and Facebook its chief operating officer, but Google only offered its chief legal officer and senior vice president of global policy, Kent Walker. Committee chair Sen. Richard Burr (R-NC) refused to accept Walker’s presence or testimony, and as a result, Google appeared only as an empty chair — and the subject of heated criticism from committee members.

Several senators chastised Google, and Sen. Mark Warner (D-VA) in particular offered a litany of Google’s failures, including “absurd conspiracies” appearing in Google Search and “countless hacking attempts” against Gmail.

Jack Dorsey tweeted his opening statement

It’s standard practice for hearing participants to post their opening statements online, but Jack Dorsey took the extra step of tweeting his testimony and then looking down during the hearing to read it off his phone. A few senators jokingly flagged the move during their questions — including Burr, who commented that “as you grow older, you will find a need for a bigger device to go to your notes on.”

Thank you Chairman Burr, Vice Chairman Warner, and the committee, for the opportunity to speak on behalf of Twitter to the American people. I look forward to our conversation about the work we’re doing to help protect the integrity of US elections, and elections around the world. — jack (@jack) September 5, 2018

Twitter and Google got grilled over election micro-targeting

Sen. Ron Wyden (D-OR) raised one of the major concerns with Facebook’s large-scale data collection: the possibility that political groups could suppress voting by targeting misinformation at very specific groups of people, potentially by providing false information about voting. Democrats on Twitter, for instance, have been targeted with ads claiming they could cast a vote by text message.

“There is a long history in this country of trying to suppress civil rights and voting rights, and that activity has no place on Facebook. Discriminatory advertising has no place on Facebook,” said Sandberg. Pressed for detail about what Facebook was doing about the problem, she cited a mix of automated systems and human moderators reviewing ads — Facebook’s standard answer for dealing with bad content.

Senators asked platforms to fight bots and deepfakes

Automated accounts and AI-generated misinformation are potentially less controversial targets than actual human content, and senators asked Dorsey and Sandberg about both. Sen. Warner asked whether Twitter might implement a system of labeling automated accounts, which Dorsey said “is an idea we have been considering over the past few months. ... we are interested in it, and we are going to do something along those lines.”

Later in the hearing, committee members also tackled “deepfakes” — realistically faked video and audio that could erode trust in real recordings. Sen. Angus King (I-ME) asked Sandberg whether Facebook could determine whether a video had been manipulated and tag it for readers, warning them that it may have been faked. Sandberg offered a general response, saying that “as always, we’re going to do a combination of investing in technology and investing in people, so that people can see authentic information on our service.”

Marco Rubio suggested he’d beat up Alex Jones

Commentator and conspiracy theorist Alex Jones attended today’s hearing alongside a few other far-right figures, and after it ended, he got in a brief but intense verbal altercation with Sen. Marco Rubio (R-FL). Jones was recently banned and suspended from several major platforms for posts that the companies determined contained hate speech or incitement to violence, including a video that urged supporters to get their “battle rifles” ready. And as highlighted by Daily Beast reporter Will Sommer, Jones appeared at a post-hearing interview session and heckled Rubio with questions about his bans.

Here's video of the Alex Jones - Rubio spat https://t.co/lGDaHAcZUc — Will Sommer (@willsommer) September 5, 2018

Rubio repeatedly claimed to have no idea who Jones was. Then, when Jones patted Rubio on the shoulder, Rubio told him off with an implied threat: “you’re not going to get arrested; I’ll take care of you myself.” The exchange ended with Rubio leaving in bemused disgust while Jones accuse him of being a “frat boy” who should “go back to [his] bathhouse.”

Dorsey says Twitter’s rules are too confusing

During the day’s second hearing, before the House and Energy Committee, a congressman asked Dorsey about Twitter’s historically inconsistent application of its rules. Does the average person understand them?

Dorsey conceded the point. “I believe if you went through our rules today and sat down with a cup of coffee, you wouldn’t be able to understand them,” Dorsey said.

A far-right activist interrupts the proceedings

Alt-Right conspiracy theory peddler Laura Loomer just crashed Jack Dorsey's Congressional testimony.@USRepLong began mocking her pic.twitter.com/aQiAwnmeoE — jordan (@JordanUhl) September 5, 2018

The House hearing was briefly interrupted by a far-right activist who filmed herself shouting accusations of bias at Dorsey, presumably for future use on her social media accounts. The activist, Lara Loomer, is best known for a racist tirade against Muslims that earned her a lifetime ban from Uber and Lyft.

After Loomer began yelling, she was drowned out by Rep. Billy Long, R-MO. Affecting the voice of an auctioneer, Long proceeded to conduct a fake auction until Loomer could be removed from the hearing room.