In all events, Mark doesn't risk anything. Even if the stocks of Facebook were collapsing, he'll still be billionaire, and even if he was ending with "only" some hundreds of thousands of millions that is still good enough for a living, so why would he mind.
Interesting set of links. Noted that Breitbart, Daily Caller, Daily Wire, Drudge, and others of a different bias were not suggested.
As for the "testimony" there was little in results: a lot of fillibustering, posturing ON BOTH SIDES. What has happened, however, is the door has been opened and a whole list of items has been expressed. Somewhere down the line it's possible actions will be taken ON BOTH SIDES.
MZ's pat answer of AI to solve things as if it were god-like is disingenuous: humans write the algos for the AI! How it works is what humans intend.