I think Twitter, more than Facebook and Google, really has been the advocate for free speech. Certainly each company has corporate overlords (i.e. investors) to answer to. Yet, Twitter as a medium is built for instant news. It’s ease and terseness inspire bursts of expression reminiscent of the CB radio communications that inspired Jack Dorsey.
These tech giants, who now safeguard our 1st amendment, has had to battle governments around the world. Google, for example, defied the mighty Chinese politburo. Yet Twitter, more than Google and Facebook, showed its moxy and grit by fighting our own government.