It is far more likely that Bezos and Zuckerberg support Trump than fear being shot. Zuckerberg particularly, what makes you think this was a 180? The man has been doing machismo stuff like throwing spears at goats and challenging people to boxing matches for years. And have you seen the way Facebook is moderated, even years ago relative to the way Twitter was moderated under their old owners? Supporting Trump is in-character for Zuckerberg, even more so than Bezos.

I must say though, this "billionaires as terrified victims" narrative is hilarious. I hope the Democratic party rescues these poor billionaires from the man they're publicly supporting!

Should ownership of newspapers be limited to mere millionaires? Or do you mean that private ownership of newspapers should be abolished?

This country was built on privately owned newspapers wielded as weapons by their owners; I'm sure you've heard of Benjamin Franklin. The First Ammendment protects this more than anything else for this reason.