According to this report, a Harry Potter fan known as MsScribe pulled off an elaborate Batman Gambit involving an untold number of sockpuppets to garner sympathy, advance her popularity, and secure her place in what was then the fandom's inner circle.
This can be an effective way of dealing with Internet trolls. Set up the right conditions and they'll possibly admit to trolling (in an attempt to grief you) or saying something incriminating that can get them modded (often happens when they brag) or used against them — such as one review troll who after being accused of not buying the game, admitted he had bought the game to play it and piss everyone off. Said review troll's credibility was destroyed, and most of his reviews were removed.
One way people manage to get more money from their items sold on Ebay is to get a friend's account to bid alongside genuine bidders; this gambit would assume that the genuine bidders wanted the item enough that they would bid higher when the "friend account" offers a higher price.