For example, when you see someone creating a big discussion in a post, blog or social network that is leading nowhere, then someone might call the person who is disturbing the peace an "attention wh..re."

Yes, it's used for someone who always does something to get attention, or loves attention. This can include show-offs, but also drama queens. Obviously from the word "whore", it's a negative thing to say about someone. From various blogs: "Bodybuilding is full of attention whores. You will fit right in. Just Sayin'." "SELFIES: Do they prove you are an insecure narcissistic attention whore begging for 'look at me' validation?" "And this attention whore... just wants to be famous because he's a sh*tty lawyer and nobody will hire him..."