A comeback used against someone trolling on a website.
Troll bait "your retarded"
Troll "it's you're* not your. Whose retarded? (sic)"
Trollback "its who's not whose. Let the circle jerk begin lol"
The result of writing a undefined + sign before rollback resulting in hilarity.
My notes say "fix prediction trollback". I think the t is supposed to be a +, but I'll spend 30 minutes googling "trollback" just in case