That's the tip of the iceburg in terms of pirated software. They can never stop it. $100 million is nothing compared to EVERYTHING that sits on FTP boards, IRC, and even programs like Morpheus. It's sooooo easy to pirate right now that you don't even need connections to get on good boards, just Morpheus.
This isn't warez, its actual pirated software... as in the ones in counterfeit boxes with manuals. Big difference. Warez aren't targetted unless the idiot gets careless and puts it on a school's server. They know warez are mainly an adolescent activity, people who normally wouldn't buy the software anyways, so there's no actual loss there. Pirated software however is counterfeited items, and a lot of times, people don't know the software they are buying are actually pirated... or they don't know the difference. Here there is a real loss, because you're actually take real sales away through these pirated software.