I can't find anything from a remotely unbiased source on "facebook hires censors" other than this: https://www.popsci.com/Facebook-hiring-3000-content-monitors

Which is basically just content monitoring that AI can't do... child exploitation, hate speech, gore, pornography, etc.

I think it's a pretty damn right-wing slippery-slope you're traversing if you assume that's equivalent to "censorship of rogue ideas"

“Hate speech” seems to cover a pretty wide spectrum these days.

Fair enough because I agree, nevertheless it’s a stretch to accuse The Social-Network Powers That Be of essentially a left-wing conspiracy

The bias makes sense and I wouldn't call it a conspiracy theory. Where are the censors hired?

Californians have a different idea about hate speech than people from Alabama who have a different view of hate speech than someone from Bangalore.

So if you hire your censors from California you are going to see right wing rogue ideas considered hate speech.

I know tastes differ across space, but there must be some minimum standard that would satisfy almost everyone

Of course there is a minimum standard - but the problem is to have effective censors you need to give them a degree of leeway/self-judgement and in a politically charged environment this will lead to bias.