I don't want to discuss whether piracy is or isn't a problem, and whether publishers have the right to include copy protection in their programs.
What I'd like to know is has there been any info on what type of DRM will be used with D3?
How likely is it that D3 comes with similar DRM to Bioshock, Mass Effect, Spore, and so on?
My opinion is that the DRM that comes with the mentioned games is much too restrictive. In fact, I do not (and will not) buy games with such DRM. With Mass Effect, you are effectively renting the game. Since D3 will obviously have a huge online component, I think that Blizz doesn't need that type of DRM, even if they think they do, since a large majority of players will be logging online to play. A simple CD check to logon to battle.net would suffice.
Looking back at previous Blizz games, I don't see a very restrictive type of DRM, which gives me hope that they will follow that trend. However, times are changing, and more publishers are using excessive DRM. IMO, it isn't to combat piracy, it is to gain control they'd otherwise be scolded for, and to try and move as close as possible to a subscription model since that is more profitable.
Has there been any info or clues dropped, either during the WWI, or prior to it, that would shed some light on their plans for DRM in D3?