Twitter/Facebook/the internet in general has made it so easy to hurl insults around with nearly zero ramifications. We're all guilty of it. Maybe you watched a terrible movie or saw an awful concert and decided to tell it like it is. Well next time you do that, maybe you should first think of the celebrity you're insulting.
Jimmy Kimmel compiled a bunch of insulting celebrity tweets recently and got the celebrities to read them. Feel pretty bad about that awful tweet now, don't you?