In Germany you cannot advertise nazism, which you can in America. This restriction of free speech in Germany is exactly put in place to prevent a totalitarian state.

It's a bad idea to do that. To prevent a totalitarian state, there should be general and abstract rules that prevent advertising things that lead to a totalitarian state.

Having specific restrictions for nazism can have the opposite effect: people think everything is fine because there is no nazism, but other groups, using similar dangerous schemes will not be regarded as dangerous.

I found it interesting that the last time I was in Berlin, about a year ago, I kept finding the same stickers everywhere being used for vandalism, initially with an anti-fascist message and then just as many cleverly scratched over to change the message to anti-Semitic hate speech.

Equally interesting was that these things were everywhere and none of the locals I was with had ever seen them before. Out of sight, out of mind.

I am not convinced that it helps preventing totalitarian state, quite the contrary.

De-platforming is not removing freedom of speech.

It is simply one private entity using freedom of speech to say that it will no longer act as an amplifier for another private entity's speech.

Trump can (and likely will) continue to speak freely.

I totally understand that Twitter is a private company which can do whatever they want.

But the world changes and they (and too few others) are becoming de-facto platforms for speech exchange. And this needs to be properly regulated to make sure freedom of speech is not in danger

Freedom of speech is a means, not an end. It's a tool that we can use to shape society as we see fit.