It could be potentially quite serious I reckon Pete, even though America has helped the muslim countries at times, they are still viewed as interfering by many who have not welcomed the help for whatever reasons.
This unrest has been going on for quite awhile now and seems to have spilled over.
I haven't really read up on what was exactly in the film, but I believe the person who made it is being questioned?
It wouldn't hurt America to apologise if they haven't already done so, and condem the film as inappropriate if that is what they think it is --- or do they???