1. It can be crocodile indignity, which is basically a political tool to further oppression and to establish the position of the "offended" one as a master who makes the law. This happens on personal level when some indignant person is the abusive bitch, for example, or on public level, in the political correctness movement.

2. It can be due to someone genuinely feeling hurt. That's mostly due to insecurity and neurotic trauma.

Not sure if this is a new problem, but it's played a lot more in the media than it used to be. Probably for the usual reason, someone is "telling us to behave".