Because ultimately the only things that sends people to the streets are things that truly threaten their freedom or existence. Does anyone really care about movies or music enough to cause riots? My opinion is that if it really comes down to brass tacks, people would more likely stop listening to music and stop watching movies before they riot.

However, I realize this is not the point, this is the start of a slippery slope. If they can curtail freedom of expression in this instance, what other instances will they think they can curtail it also? What does that lead to? Eventually all freedom of expression could be removed based on a single precedent - is this that precedent?

Further to this, if all freedom of expression is removed, what then? When people can't express themselves freely, is that cause for a riot? That depends largely on the culture of the country - so is Spain a country that's likely to riot if their freedom of expression is removed? Only those that grew up there and live there every day can answer that question.