Free speech doesn't mean people have to listen or even give you a platform. Nobody but the government is bound by the first amendment. Read up on the laws you're talking about.
I'd prefer the court system decide who has broken which laws, rather than domain registrars or random internet commenters.
Pretending you and your allies can quasi-objectively categorize "extremists" is exactly the sort of mass delusion we need free speech to prevent.
In a sense it's even paradoxical. You can't say that everyone must uphold free speech on every subject without restricting their own freedom in some way.
Why would this paradox arise in a just society? Specifically the second condition.
My (Kantian) ethical justification for the first is "in any situation where I use the rule, I would want its use to be universally established", whereas in the second condition it is clearly false to say that every situation where I restrict someone else's speech coexists with my desire for everyone else to decide when another's speech should be restricted, since my desire to censor and my opponent's opposite desire would contradict that I am acting how I would if I wanted the rule to be universal.
Isn't the only freedom you're restricting by upholding free speech, the freedom to arbitrarily restrict freedoms all for the sake of promoting big-picture freedom? I find it hard to see this as consistent. What kinds of scenarios do you see as too messy/exceptional/extraordinary where freedom of speech becomes a self-imposed restriction?
It's not about "freedom" to restrict others' speech- it's about freedom not to support it or to listen to it.
That said, there is an argument to be made that a host should not worry that they are partly to blame for, or that their non-intervention suggests tacit approval of, a user's detestable messages - simply because the host just isn't accountable for the user's actions. The solution to not supporting it, imo, is to be explicit about the host's scope of permissions and banned content right up front, before problems occur, because then the responsibility for the user to not do so is recorded. [If the agreement clause is really vague and allows nearly anything, it doesn't change that the user can expect it to be used.]
Freedom to not listen to speech is in my opinion just as valid as the freedom to speak; maybe I'd call it the freedom to silence :P
[An extreme example of Kant is that, if a murderer asks, you should tell them where the person they say they are going to kill is, instead of lying. The reason goes: right and wrong having nothing to do with morality (universal law) so you can't justify lying to the murderer if you see them as a person who is an end in themselves- rather the lie is a way to pursue a right and wrong based in single situation hypotheticals (whether you should manipulate the murderer to save lives), which means it can't derive its value to you from being universally applicable, from not originating from a categorical truth. The reason although people are worth more than a means, you still can't mislead the murderer so as to protect a valuable life, is that the potential murderer, also an undeniable end in themselves, is the one upon whom the responsibility for the murder should be placed - you are not responsible whether or not the murderer tells the truth that they will kill or if they lie. They are still totally free to choose not to murder the person after you give their location away anyway. Do I think I would act this way? I really don't think so. Another way to resolve it is to keep quiet lol]
This sounds like a conundrum to me. If you think groups should not have free speech if they don't support free speech, then you don't support free speech and shouldn't be allowed to speak.
"your freedom of speech ends where the freedom of speech of others begins"
Because principles only count when they're uncomfortable to uphold. A principle that is only exercised in defense of the already-palatable is hollow and worthless.
There can be exceptions to principle, but each one is an encroachment that rightly raises questions whether the person making the exception is shirking responsibility.
The most palatable cases are when both principles co-exist in a way that they minimize the amount they compromise eachother's purpose.
For example: A defense of copyright creating a limit to free speech generally rests on an argument that such a restriction doesn't undermine purpose of free speech. The argument assets that free speech is primarily about sharing ideas that are contemporaneously unpalatable, or disruptive/subversive to existing power structures. Copyright doesn't prevent a speaker from expressing ideas also expressed in copywritten works, and it even offers many ways in which a speaker could quote a protected work verbatim.
On the other hand, structuring bounds of speech as "free, except when I really don't like it" is harder to defend as a commitment to free speech. It is counter to the very purpose of free speech to defend the unpalatable. There is certainly an argument to be made here that a limit both has a good reason and minimizes the amount of speech it preempts, but nobody is presenting one. And until they make that case, and make it very convincing, others are right to consider it an abandonment of principle.