An internet forum self-image defense strategy. Used by someone has been clearly proven wrong, stupid, or idiotic on a forum over the course of multiple posts or threads. The person realizes how foolish they now look, and default to claiming their entire dialog was a troll. Even though they claim it was a troll, it is very clear and obvious that it was not, and they simply have nothing left to retort with.
Person A: "You are a dick"
Person B: "No, sir, YOU are a dick. Here is why, with facts"
Person A: "lol, trolled you good fucker!"
Person B: "Nice Farva Defense"