All I'm saying is that "freedom of speech" does not alter/legitimize overtly discourteous behavior. If you actually asked these people why Obama is like Hitler, which happened a few times and was reported, they either don't know or have crazy ideas. Seems to me that many of them saw an opportunity for mayhem disguised as "freedom of speech" with the possibility of a few moments of fame. The more attention they receive, the more likely it is they will do it. That's not just the US, either: these sorts of people are everywhere and while the US contingent may be content to wave signs, others can be far worse.

In case of any misunderstanding: I'm not talking about you. Clearly you hadn't just listened to Rush and decided spontaneously that Obama is a closet Nazi, but nor did you turn up to insult your Representative or Head of State by attending a civilized meeting to disrupt and wave deliberately obnoxious signs at them.