Yeah, right. Whether or not a pirate is really enjoying a game he's just downloaded and installed is a mute point, because I don't for a second believe that anywhere near a significant number of them will then go and buy it as a consequence. Not when it's something they technically already own.
Technically, they don't actually own it. Ownership is a legal term. They simply possess it. In any case, I agree that most people won't buy something they already have. The question is whether or not pirates would have bought what they have had it not be freely available. I'd say no. People are cheap. They are also lazy. If you make the official product more convenient than the pirated one, people are more likely to buy the official one. However, publishers are forcing legitimate customers to deal with CD-keys, online activations, limited installs, constant internet connection requirements, etc. Meanwhile, pirates don't have to deal with any of that. Publishers will never beat pirates when it comes to pricing but they can beat them when it comes to convenience. Just look at the success of Steam. Ubisoft needs to learn that treating customers like thieves isn't going to increase their sales.