I think most everyone agrees that such behavior is illegal, and wrong. Those folks at the demonstrations are emotionally charged and lost their temper. That is a different case. I don't see anyone saying it is illegal to simply dress like a Nazi, or even admit to being a racist.
Rather, many people just disagree with the Nazi message. That is not illegal either. It is also well protected, free speech to denounce Nazi behavior in every way possible if you feel it appropriate.
Kinda like this guy born in Austria, 1947!
Now he should address the Communists as well.