I can see why ID would complain - Single player games are by far the easiest to pirate. Games Liek Fear and Prey were extremly easy games to pirate, and you only really need a keygen and a no-cd/fixed-image. All the steam based games are hard to pirate, and in fact i just bought them cause I liked them (games, not steam) so much. Despite the annoyances of steam, it does an excedingly good job of preventing pirating. Also, games like BF2, which only have an online multiplayer worth playing, can check cd-keys on login, and are also difficult to pirate.