Haters, assemble!!!

Jokes aside, I want to know what drives you to inform the rest of a website, chat, forum, or thread, that you don’t like/enjoy/want/do something.

I wanna hear what your impetus is.

Is the act cathartic? Do you have a personal, negative experience with the thing you’re complaining about? Is the impulse automatic or do you think about it every time?

The question is only as serious as you make it, but I’m curious all the same.