In my humble opinion it's a bit stupid of the protesters. They watched a video which portrayed the founder of their religion (whose values they follow) as a violent and aggressive bigot. To try and stop this, they were violent, aggressive bigots; can they not see how that slightly undermines their own argument there? Then they don't seem to realise that if they hadn't kicked up this huge fuss about the video nobody would have seen it, they just advertised a video they see as offensive.
I also agree with Jubal, they clearly have no idea how western society works, as they saw content made by someone in the US and immediately blamed the US government, which isn't quite how things work over here. That and the poor quality of the video should really have told the "protesters" that this wasn't the doing of a large organisation...