Ubisoft has been annoying PC gamers with its DRM for quite awhile now. PC gamers will find more reason to sulk about the company's attitude upon the discovery that Ubisoft's limited activation scheme is not only machine specific, but also hardware specific. Specifically, the DRM will know if you've replaced a graphics card.
A game like Ubisoft's Anno 2070 will not run if and when you swap out a graphics card. For gamers who regularly update their systems, such an action can render every game in their Ubisoft library worthless. Guru3D discovered this DRM 'feature' while they were trying to run a benchmark on the aforementioned game.
According to the website, the game simply stopped working when they swapped out the card. Attempts to reinstall the game and reactivate it were met with failure, as the DRM had assumed—wrongly—that the copy-protection was tampered with.
The company's insistence on implementing heavy-handed DRM into its games has earned it a formidable amount of ire from the PC gaming community, especially since the games it releases on Steam already come with their own copy-protection, courtesy of Valve.