Our prisons are primarily filled with unpopular people. We tend to refer to them as minorities. Some specific examples off the top of my head of intentionally vague law is when there's purely subjective decisions as to whether a crime is just a "regular" crime or a "hate crime." There also seems to be a lot of ambiguity around what exactly constitutes copyright infringement or the legal vs illegal varieties of hacking.
Agreed, our prisons are full of unpopular people (though that's kind of circular, because being in prison makes you unpopular).
Good point about minorities, though that's largely because of uneven enforcement of laws (e.g. blacks tend to receive harsher sentences, and are more likely to be busted for minor drug use) and arbitrary laws that are more likely to affect them (e.g. crack cocaine being treated way more harshly than powder cocain). It's not because the laws are vague (not to imply that that makes this acceptable) since vagueness is way for a law to be struck down. For example, vagueness is one of the primary arguments being made in Weev's case against the CFAA. (Don't know enough about hate crimes to comment, and copyright infringement is mainly a civil, not criminal, matter.)
