Just goe to show that the city of Boston is full of idiots. The plaster the same things all over Austin and no one freaked out. Some people take themsevles way to seriously.
Regardless of how dumb we might think this is, the two guys shouldn't have acted like complete jerks in dealing with the situation. I think this, more than anything, is what made people angry. Apologize and say you didn't mean for it to be taken a certain way and it will go away. By going out of your way to be an arrogant jerk about it, you just add to the overreaction.
People were angry and over reacting long before those guys were even arrested. Plus, these guys are actually facing a trial, last I heard, and can't just pay 2 million and make everything go away. So instead of saying "no comment" multiple times, they pointed out the absurdity of it all.