Think of all the recent widely publicized demonstrations. Students in London riot because they're being asked to pay for a larger share of their college educations. Greeks riot because of the austerity measures needed to save their extremely overextended country. Public employees in Wisconsin occupy the Statehouse because their pensions and benefits might be brought more into line with the private sector which pays for them.
Then think of the demonstrations which took place forty and fifty years ago. Students demonstrated against the Viet Nam War. Blacks marched to protest segregation.
A rally for true justice is more justifiable. Today's demonstrations are more often about hanging on to special privileges.
Years ago, Americans would have been embarrassed to riot about keeping their fat pensions. It would have felt greedy.
As recently as 2003 Americans marched en masse to protest the imminent invasion of Iraq -- to preserve peace and avoid bloodshed. But the trend in demonstrations seems to be more and more towards narrow self-interest.
It gets harder and harder to muster any sympathy for the protesters. Public employees now make more money than those in the private sector. The cause of civil rights has long since been turned on its head. A demonstration seem to be an excuse for indulging one's inner vandal rather than for protesting any real injustice.
That brings me to another telling point: the best way to judge a demonstration is by the amount of property damage and the trash generated by the demonstrators. It is almost always directly proportionate to the self-indulgence of the cause.