I was stuck behind a guy in a Prius this morning with his bumper covered with sanctimonious bullet points. Don't get me wrong, I like the idea of fuel-efficient hybrid vehicles in theory. It just seems that in practice, the reduced emission of smog is more than offset by the increased emission of smug.
Anyway, this particular driver had a sticker saying "Overpopulation: #1 environmental problem." And it struck me: people who say this never seem to be willing to do anything about it personally.