Trump threatens to 'close' down social media platforms

That’s probably why they’ve delayed taking this stance for so long. They have, after all, typically refrained from “fact-checking” leaders or politicians in other countries too. I assume it’s just got to a point where they’re no longer to (in their good conscience) offset readership/users with the promulgation of highly questionable statements.

And to be perfectly honest, I’m all for it, especially if they’ve done this (and will do this more broadly, as you suggest) despite expecting to take a substantial ‘hit’ to their bottom line.