Well, turn the automagic updating of the banlists off then. It's configurable, but it's not the default because most people are not interested in seeing the posts of (as an example) people who upload kiddie porn, nor do they want that on their hard drive in the off chance the FBI comes by with questions.

So the possibility of highly illegal content justifies a block list which perhaps includes mainly blocking unwanted political opinions? That argument sounds familiar.

I think the point is that the blocklist is optional. If you don't like it, don't use it. Or make your own that is more directly tuned to your tastes.

It's the default, and I guess people mostly won't notice if it blocks too much. So the effect would be pretty similar.