The Same as saying "I don't give a fuck".
Person 1: "Don't you know that we could all the starving african children if we used the ceral crops used to feed animals to feed people and stopped eatting meat.
Person 2 "You own guns?!?!? Don;t you know guns kill people?"
A question without meaning but yet provocative.
I was walking in a bar and some dude bumped into me, I turned around and said "AND?"