You’re stopping a someone from making a huge mistake. That’s not evil, that’s doing them a big favor.

For bonus points, be there when they do it, so that when it happens you can convince them that it's IE's fault, and get them to use Chrome/Firefox instead.

They'll figure it out eventually, but by then they'll probably come to like Chrome, and stick with it from now on. There, you've just saved yet another person from IE.