No one tries to pwn Anderson Cooper and get away with it -- except for rapper M.I.A., who clearly didn't realize who she was dealing with and tangled with Cooper in March when she thought he called her a terrorist.

It all went down when M.I.A. told her fans to watch the documentary 'Sri Lanka's Killing Fields: War Crimes Unpunished,' which follows the Tamil Tigers -- a group made up of people who are either terrorists or revolutionaries, depending on your perspective.

M.I.A. (a Tamil Tigers supporter) suggested that Cooper watch the program to see how respected journalists often get their info wrong, claiming he called her a terrorist in 2009 for expressing sympathy for the group.

Anderson asked her what the hell she was going on about, and she replied.

Cooper said he even defended her Super Bowl stunt in which she flipped off the audience.

An obviously confused Cooper called M.I.A. out on her flip-flopping and laid out the facts for her.

She responded once more ...

... and then POOF. It was over.