As a long time PC gamer dating back to the C64 days, I know the piracy scene from seeing it first hand. There was a ton of it back in the day and there were many attempts at curbing it on that system, which was easily bypassed by pirates. Much like today it seems.
CD Projekt, makes of The Witcher
series, talked with PC Gamer
on why DRM is just not worth it. It hurts the experience for legit purchasers and any DRM is going to be broken in a few days anyways.
The CEO estimates conservatively that they've had The Witcher 2 pirated about 4.5 million times, but he knows there's nothing that can be done about that. What he does know is that if you make the game good and offer good value, people will buy it.
It's good to see a company know how to handle the issue rather than try to fight it tooth and nail when they aren't going to win. The way to go is to churn out a high quality product that's worth the money and offer things that make it compelling to buy it. The more you try to lockdown a product, the more someone's going to try and break it and in the end, it's going to end up on the Internet no matter how hard you try.
If you're in the software business, just expect your product to be copied. It sucks if you're a developer, but it's going to happen. But, if you want to stay in the business, you can still profit really well and you'll catch more buyers with honey than vinegar.