"It's a tie for first place between:
"political correctness
lawyers (and I'm talking about the kind of lawyers that claim damages for morons who can't drink a cup of coffee or walk down the street without injuring themselves)"
Those are in the top three for me too. Also in my top three are fundamentalists.
PC and fundyism are two sides of the same coin: the intent to engineer how people think. But I must say they are more than a "pet hate", they are a serious problem. Same with those lawyers you mention who are promoting irresponsibility and unaccountability to oneself. A few more generations of THAT and people won't know how to wipe their ass....
Other serious problems: when technology is used to invade privacy (actually ANY invasion of privacy); corruption; no rule of law (i.e. when laws don't apply equally to all members of society); intellectual (or any) dishonesty; and the desire of some people to wield power over other people (rather than true leadership).
Stuff in the "pet hate" category: people pissing on the toilet seat rather than lifting it up; women who b*tch when the seat is left up (how hard is it to pull it down?); people making out in public (kissing is okay IMHO, but when they get all hot and heavy they should get a room); people who plead that they should be trusted (if they must do that, usually there is a good reason for that...); people who won't tell you either the truth or what they feel to your face, because it might "hurt" you, and yet this data is important to your decision-making; intellectual snobbery ("who the hell do you think you ARE b*tch!"
); and people who let their kids get away with anything!!!!
