-Part of a Fandom/Group
-Just plain better than them
How they operate is simple. To bring up pointless, nonsensical facts about a certain topic towards a person, usually against that topic. They all have a catchphrase (which is really stolen from Trolls nonetheless), "U Mad, Bro?". This statement is the blind truth that these people have nothing better to do with their time on the Internet.
Girl: That's awesome! Can I se-
Hater: Faggot! Why don't you go jack off to your anime crap you yiff!
Girl: What did you say to my boyfriend...?
Hater: U Maaad, Brooo?
Person: Actually, I think you're the one who's mad because compared to me... And many others... You just suck.