jefequeso: I'm speaking in a purely legal sense...please don't take this to mean that I'm supporting or advocating the KKK.
But as far as I know (and I'm really not a legal expert), they're protected under freedom of speech up until they actually do something illegal. And to be perfectly honest, I don't think I'd want it any other way. It's too easy to push that sort of thing too far. At first, maybe exceptions are being made for terrorists or hate groups...but once a leading power gets the freedom to adjust its core laws as it wishes, there's no telling what sort of crap might happen. It's a realy shame, but that's part of the price of freedom of speech. You have to take the bathwater with the baby.
jamyskis: No, any utterances or writings that are deemed a breach of the peace are excluded explicitly from the First Amendment by way of precedent (said precedent being, I believe,
Chaplinsky v. New Hampshire - I could be wrong though, as my field of expertise is German law, not US law). Therefore, if any manner of expression serves to bring about a breach of the peace (e.g. by inciting or provoking someone to commit a felony or misdemeanor, cause panic etc.), it is explicitly not covered by the First Amendment.
The key here is the issue of "prior restraint" - the outright forbidding of making a statement regardless of its consequences. We have plenty of examples of prior restraint in German law (German gamers will be familiar with one of the most famous and notorious examples: Article 131b of the German Criminal Code, forbidding any publications that glorify violence), although for the most part it has worked out pretty well for us.
I personally think that the First Amendment has outlived its purpose and needs to be replaced with a more relevant law. These days it's used for nothing more than as something for cowards to hide behind when they don't wish to be held to account for their actions. Just because the First Amendment prevents prior restraint does not exempt one from the consequences of one's actions.
I do agree that restricting freedom of speech can be the start of a slippery slope though. I think the German constitution gets it completely fucking wrong in the other direction. I quote Article 5:
(1) Every person has the right to freely express and disseminate their opinion in oral, written or pictorial form and to educate themselves without hindrance from generally accessible sources. The freedom of the press and the freedom to report by means of broadcast media and film are guaranteed. There shall be no censorship.
So far, so good, right? At least it is until we get to number 2...
(2) These rights shall be restricted by the provisions laid out in general statutes, the statutory provisions intended to protect young people and in the laws protecting the rights of the person.
Just as an explanation: "Allgemeine Gesetze" (general statutes) means the overarching laws that serve the general well-being of the people.
So basically we have a useless constitution that allows the government to enact any law restricting freedom of speech under the pretense that it serves the general public, the rights of the individual or in the interest of young people.
That's odd that your constitution calls out one specific age group. Are young people considered extra important in German culture? I don't know anything about German law either.