Facebook's Sheryl Sandberg, Twitter's Jack Dorsey head to Capitol Hill

During a set of hearings, Congress intends to demonstrate that it won't let Silicon Valley's growing influence in politics go unchecked.

Two of Silicon Valley's most prominent executives will appear before Capitol Hill on Wednesday to defend their social media platforms. Lawmakers from both sides of the aisle are sure to have tough questions for Facebook COO Sheryl Sandberg and Twitter CEO Jack Dorsey in a set of hearings -- the latest opportunity for Congress to demonstrate that it won't let Silicon Valley's growing influence in politics go unchecked.

First up, the Senate Intelligence Committee will have the opportunity to grill both Sandberg and Dorsey over "foreign influence operations" on social media. Later in the day, Dorsey will take the hot seat before the House Energy and Commerce Committee, where he'll field questions about political bias on Twitter.

In the Senate, Sandberg will pick up where Facebook CEO Mark Zuckerberg left off in April, when he testified in a rare joint hearing of the Senate Judiciary and Commerce Committees, as well as before the House Energy and Commerce Committee. Like Zuckerberg, Sandberg is prepared to tell Congress that the social network is making substantial, long-term investments to root out bad actors and "inauthentic behavior."

"At its best, Facebook plays a positive role in our democratic process--and we know we have a responsibility to protect that process on our service," Sandberg's opening statement says.

The statement, which Facebook provided to ZDNet, notes that Facebook now has more than 20,000 people working on safety and security issues. The company reviews reports in over 50 languages, 24 hours a day. Meanwhile, improvements machine learning technology and artificial intelligence have enabled Facebook "to be much more proactive in identifying abuse," Sandberg's statement says.

The hearing follows reports that Facebook plans to establish a physical "war room" where staff can find and destroy attempts to meddle with upcoming elections.

Google's chief executives will be conspicously absent during the hearing: The Senate Intelligence Committee asked the search giant to send one of its top leaders; senators, however, were dissatisfied with Google's offer to send its chief legal officer Kent Walker. Sen. Mark Warner of Virginia, the top Democrat on the committee, has said there could be an empty chair placed next to Sandberg and Dorsey to represent Google's absence.

Google, nevertheless, submitted written testimony from Walker for the hearing. Walker wrote in a blog post Tuesday that as Google's "senior executive responsible for these issues," he will be in Washington to brief members of Congress on this and other issues.

"We have continued our efforts and work diligently to identify and remove actors from our products who mislead others regarding their identity," Walker's written testimony says.

Meanwhile, in the House, Twitter's Dorsey will have to answer to Republicans who are unhappy with the platform's treatment of conservatives. The GOP majority said it plans to ask, among other things: how Twitter monitors user accounts for compliance with its user agreement, as well as how the company ensures it doesn't stifle freedom of expression for "views that might be unpopular with its owners or employees."

Dorsey, in his opening statement, stresses to Congress: "Twitter does not use political ideology to make any decisions, whether related to ranking content on our service or how we enforce our rules. We believe strongly in being impartial, and we strive to enforce our rules impartially. We do not shadowban anyone based on political ideology. In fact, from a simple business perspective and to serve the public conversation, Twitter is incentivized to keep all voices on the platform."

That said, in an interview with Politico on Tuesday, Dorsey and Twitter policy chief Vijaya Gadde said that no one is above Twitter's rules -- not even President Trump. While world leaders may get more lenient treatment on the platform because their statements are generally considered newsworthy, there is no blanket exception for the president or anyone else," Gadde said.

Dorsey declined to say what role he would personally play in such a decision. "We have to balance it with the context that it's in," he told Politico. "So my role is to ask questions and make sure we're being impartial, and we're upholding consistently our terms of service, including public interest."

While Wednesday is sure to feel like a long day for Sandberg and Dorsey, it certainly won't be the end of congressional scrutiny over Silicon Valley. In an interview with Wired, Sen. Warner shared some of the unanswered questions he has for Google's senior leadership: "I was going to ask them why Google is building a search engine for China to allow Chinese censorship. Maybe they don't want to answer some of those questions. But if Google thinks we're just going to go away, they're sadly mistaken."