Alex Jones, for example, has been removed from YouTube and Facebook.

He's still the top result on Google.

The parent comment is suggesting that there are topics that there are topics wich would get him banned just for mentioning them.

People have been punished here for answering a very similar question to yours (https://news.ycombinator.com/item?id=19945640). Even mentioning Alex Jones is very risky. And depending on the answer to your question might actually get you sued, at least in europe.

It's become impossible to say things you're legally allowed to anywhere but very fringe places on the web. [inb4 "private company etc etc": Sites can police speech as they want. Still it's a shame.]

His account has been removed, but there's still lots of content on Facebook discussing him and his ideas. There are also still lots of people on Facebook who discuss similar ideas. TikTok, on the other hand, has banned/deplatformed certain classes of ideas.

I would get banned from this site faster than I could say Meinungsfreiheit

Could you point me in the right direction? I genuinely have no clue what could be that taboo.