Modders if they work hard enough, can do anything to a game's files. Baldur's Gate was an unmoddable game when it was released, but some hard working intelligent fans made tools you they could get at the game's file and manipulate them. If someone wanted to they could make "hot coffee" for that game. All it would take is for someone to modify the creature files/animations for nudity and sexual acts. Does that make Bioware/BIS responsible for this? Now Baldur's Gate gets a M rating? No.