Piracy isn't really as bad as companies claim. Most companies charge ridiculous prices compared to what people are willing to pay. Those same people who will never pay such prices will pirate it instead. It's not hurting sales that badly. I still buy albums which I've downloaded.. heck, if a lot of the songs on the album are good, I think paying for a higher quality cassette is well worth it. But back before the price cap on cassettes, I would never have bought any albums.
It's a very blurred line. I don't think anyone really knows what the impact is. DRM is horrible; it actually punishes valid buyers more than pirates, because the pirates tend to get past that crap. Piracy in itself is bad too, without buyers, there are no games. But then again, there are plenty of games out there, even though almost all of them are available on the internet.
I think Uplink, a game about hacking, took the most cost-effective modern approach to it, by that classic code check thing. They kept anti-piracy to be minimum and a one-time thing. Doesn't take much effort to hack it, you could just photocopy it. But it's as it is.. it actually takes equal effort to pirate it as any other game, but doesn't hurt anyone too badly, not the legit consumers, nor the producers.
The best anti-piracy measure I know is Unreal World.. it's too tedious to really hack and test if the hack is successful. And it's cheap enough that people would realize that buying it is much easier than looking for a serial key.
Heh, and most of the people who argue on the side of piracy just want to justify getting something for nothing. If only the average person were so passionate about other things