>It's a huge stretch to call the existence of 4chan in anyone's best interests.

Absolutely, 100% incorrect. You obviously don't approve of 4chan's content or mission, but that's not the point. It benefits everyone when anyone takes a stand because their legal rights are under attack.

"I disapprove of what you say, but I will defend to the death your right to say it."

>This is not a slippery slope

Again, incorrect.

Any type of punishment for 4chan due to their legal content is damn close to the definition of "slippery slope". You're familiar with the "anti-slippery slope" argument already ("First they came for 4chan and I said nothing, because good riddance!"), so you're obviously cogent enough to understand what you're saying.

>The sheer anarchy of the libertarian mindset that much of this site supports is not a good thing.

This is not for you to decide. Your mindset is why free speech laws must exist in the first place.

The whole point of this is that what counts as "legal" is permitted to change. In particular, "legal under some circumstances" is a thing.