Joystiq reports Ubisoft decided to abolish its Uplay Passport, starting with Asassin's Creed 4: Black Flag. The Uplay Passport was a DRM system primarily used to prevent second-hand game sales by only offering the full game content via a registration code that was linked to your Uplay account.
"The Uplay Passport program was initiated as a means of giving customers full access and support for online multiplayer and features, along with exclusive content, bonuses and rewards," Ubisoft writes. "However, games today are blurring the line between offline and online, between what is 'single player' and what is 'multiplayer.' Based on that and on the feedback we received from you, we recognized that Passport is no longer the best approach for ensuring that all our customers have the best possible experience with all facets of our games."