Not OP. I don't think they "collude" in the traditional sense.

But every time one of the entities takes some decision or step or action, whether censorship or otherwise, it makes it a little bit more excusable and easier for others to do it and justify it.

E.g. (hypothetical)

1. Reddit bans /r/ABC for "TOS violations".

2. It's news and many reporters report on it across various articles. Some say it's due to "repeated" "alleged" "hate speech" violations, whether true or not. Probably 50% true, who knows.

3. ABC makes its own website and has a mailing list from some mail newsletter provider X because that's just what you do when you have a site and need to keep in touch with visitors/members.

4. Activists on Twitter notice. Outrage mob starts. "@X mail provider hosting known hate-speech movement" "@X mail provider...did you know you're hosting known white supremacists?" "Everybody, please stop using @X, they're supporting white supremacists!" "@AWS please look into what @X is using your infrastructure for!" ...all citing some selective articles as legitimacy.

5. Articles get written about a "movement" to have X drop service for controversial and "alleged" hate-speech website ABC.

6. X mail provider gets pressured and eventually drops service to ABC.

At this point, X mail provider probably won't get many "legitimate", "official" and "mainstream" criticisms for effectively dropping customers (even if all the mail sent by those customers on X's platform is 100% legal and innocent). Nor can their shareholders complain about losing profit because "we can't be seen supporting racists".

The problem is that each time this sort of thing happens, it adds "partial proof" of the accusations without an actual "court-like" process that decides if it's really true or not. After a certain point, it's just accepted and then carries an aura of truth/legitimacy.

Edit. Formatting.

I’ll give you a concrete example. I used to enjoy a popular anti-Obesity subreddit. People in it were impolite, but it was never worse than old-fashioned “your momma is so fat” type of humor.

It was banned from Reddit for being “hate speech” and in fact you can no longer suggest that obesity is something to be ashamed of —- on nearly any platform! Including GitHub. (but you are allowed to mock mock cigarette smokers or meth tweakers).

Which subreddit are you referring to? Based on your description, it surely can't be /r/fatpeoplehate.

He's being purposefully disingenuous. It was banned for good reason, alongside racist subs like "CoonTown".

It literally had hate in the name.