1) On web sites like this I've noticed a rule "Assume good faith". But in real life there are lots of people who say things in bad faith. In the case of PR people and trial lawyers and partisan politicians it seems to be in the job description to say things in bad faith. I have no solutions on how to fix this- I don't believe in God but I can imagine a deity punishing people who choose to exercise their free speech to profit on bad faith lies- but I have no theory of government to stop this behavior on earth.
2) We have a society based around money. People in this site like to whine about what Zuckerberg or whomever is doing but the guiding principle of society seems to be "he who has the money makes the rules". So if Zukerberg wants to weaponize Facebook against society the full power of the financial system will help him do it as long as he has the money/ property to control Facebook. I think in theory we could transition to a society where CEO and board members have their shares and/ or control of companies confiscated if they act in ways which harms society. (Perhaps putting things to a vote, i.e. a universal ballet: should Zuckerberg have his shares of Facebook seized and auctioned off under the theory he is harming society y/n)). Since this has never been tried as far as I know I don't know if my solution could even work.