I think it's a bad idea to have extremely rigid policies, because they encourage people to find the edges of those policies and ride them as close to them as possible. We're all sort of making it up as we go along.

If you're an idiot who keeps coming back over and over again making the same sort of ass out of themselves, and you can't take the hint that warnings and bans should be sending you, AND you come across as enough of an idiot that you couldn't find a proxy, then I have no problems ip-banning you. If you ban-evade but take the hint and behave well, I find myself fairly indifferent these days.