http://www.ign.com/articles/2013/10/30/some-ac4-single-player-content-requires-online-pass
SOME AC IV SINGLE PLAYER CONTENT REQUIRES ONLINE PASS
ONLINE PASSES ARE INVADING SINGLE PLAYER CONTENT
This generation is no stranger to online passes for multiplayer access and content, but it turns out that some of the single player options in Assassin's Creed IV: Black Flag are gated with Ubisoft's Uplay Passport.
In Black Flag, players can board enemy ships instead of destroying them. For players with new copies of the game, the option is available to then add said ships to your fleet; these vessels can then be commanded much like the assassin recruits introduced in Assassin's Creed: Brotherhood. However, if you're playing a used or borrowed copy of AC IV, you'll need to buy a Uplay Passport to unlock this option,Game Informer reports.
This gate also implies that the ship command mechanic will only be available with an online connection. It's also worth mentioning that the Uplay Passport required for ship command is separate from the Uplay accounts players might have from previous Ubisoft games –– this code is specific to AC IV.
Assassin's Creed IV: Black Flag released Tuesday for PS3 and Xbox 360, while the PS4 and Xbox One versions release on November 12 and 19, respectively.
Pay attention gamers, I don't want this to happen ever in video games. If you like to have your freedom, pay attention. This kind of behavior was supposed to be left behind with the XBOX ONE and possible PS4 (not proved yet).
Essay Pro