I agree, there's not much comparison to be made between Europe and the United States. There was a time when Europe mattered.
Europe and the rest of the world now say the same thing about the US, actually. Used to be, the US said, "Jump" and the rest of the world said, "How high?". Now when we say "Jump", they just roll their eyes and ignore us.
There are those who really and truly believe these attacks, around the world, that have continued after 9/11, have nothing whatsoever to do with the movie and were instead planned attacks my Muslims to coincide with 9/11. The reason for this, of course, is that the latter makes Muslims out to be bad, bad, bad, badder than ever, because this was a cold, calculated and premeditated set of attacks without any provocation whatsoever, and the mere thought that they could have been provoked is not an option. It's also convenient as a way to show that far more Muslims are of the extremist variety than are of the mode moderate variety, which is also a large part of the agenda.
But if you know and understand Islam, you know that these attacks are the direct result of the film, and that extremist Muslims have used the opportunity and the relative safety of numbers to pile on and exert their own agenda. This kind of thing happens all the time. For example, racists who could care less about dog fighting, or even dogs, used the opportunity to suddenly became PETA deputies in order to slam Michael Vick. It was so obvious as to be funny. These attacks are the same thing. Islam prohibits anything negative being said about the Prophet. Christianity prohibits the same thing about God, actually. But Muslims have a tradition (since that seems to be one of the words-of-the-day) of violent protests and exacting revenge, where Christianity, at least in it's current, modern iteration, does not (history, though, that's another matter).
Having said that, there's still no excuse for the violence. None.