"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," wrote Ubisoft communications manager Gary Steinman. "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."
Original Story: Apparently consumers who bought Assassin's Creed IV: Black Flag will have to punch in a Uplay Passport code in order to enjoy a special single player minigame. The mode within single player, "Kenway's Fleet," requires players to use a Uplay Passport code that comes with the game or can be bought from the marketplace for whatever platform the game was bought for.
When Black Flag protagonist Edward Kenway boards a ship, he has the option to add the ship to his fleet, and reap some in-game rewards. The minigame operates in much the same way as assassin recruits in previous AC titles; you send the ships on missions, and after a certain amount of time the ships return with money and spoils.
Unfortunately you have to have a game specific Uplay Passport in order to play this minigame, which is an entirely separate thing from having a Uplay online account. The bottom line is that if you buy the game used you'll have to buy a code in order to access this mode.
While this only applies to one aspect of the game that you could probably ignore altogether and not impact the single-player campaign, the special minigame is a good way for players to make a lot of in-game cash more expediently.
Ubisoft has not publicly commented on this story... We'll have more on this story as it develops. Thanks to ZippyDSMlee for the tip on this story.