I regret open sourcing an offline patch I made for an Unreal Engine 3 game. The game was unplayable due to an always online backend that got shut down, but was still being sold so I required everyone buy a license to play with my mod. I had to reimplement stock UE3 netcode, and a bunch of other really cool stuff. Someone who was mad at me for not giving them more help when they struggled to develop on my software decided to "repack" my software and the game on a popular piracy site, both violating my AGPL license and increasing the risk that the whole project gets CnDd. I guess it's funny that a project violating a companies "no reverse engineering" clause is pissed that someone violated their OSS license, but such is life :D