Expect Sandberg's answers to echo Zuckerberg's from a few months ago as well, although hopefully she won't have to get back to them on quite as much. In prepared remarks, she acknowledged Facebook's lapses during the 2016 election. "We were too slow to spot this and too slow to act," Sandberg writes. "That’s on us. This interference was completely unacceptable. It violated the values of our company and of the country we love." She then goes on to outline the various steps Facebook has taken to help fix the problem. (The process is ongoing; Zuckberberg estimated in May that it would take three years to patch things up completely.)

The House hearing will focus instead on "transparency and accountability," presumably in response to reports—so far inaccurate or overhyped—that Twitter and other platforms have inherent bias against conservatives. In his prepared remarks, Dorsey stresses that "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."

On that last point, Dorsey may take some flak from Democrats as well; Twitter is notably the only major platform not to have banned InfoWars, the conspiracy-minded Alex Jones media property that has alleged that the Sandy Hook shooting was a hoax, among indecencies. Twitter has also long been a preferred haven for white supremacists; the company has received repeated criticism for not doing enough to curtail the harassment and abuse that can run rampant on its platform. Dorsey will also give Congress a crash course in "healthy conversation," the still somewhat nebulous North Star that Twitter outlined back in March.

As you watch, it's worth keeping an eye not just on the answers from Sandberg and Dorsey, but on the questions Congress asks. When Zuckerberg took his turn at the mic, several representatives clearly had a limited familiarity with how Facebook works, and the mechanisms it uses to fight abuse. Congress may soon try to regulate the tech giants—even Donald Trump has alluded to it of late—but how can they do so if they don't grasp the fundamentals of what they would be regulating? And perhaps more importantly, how can they help these companies fight off enemies of the United States if they don't understand the threat?

It's unlikely that Sandberg, Dorsey, and Congress will resolve those issues over the course of a few hours Wednesday. But watch anyway, if only for a better sense of just how far they all have left to go.

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