The footage, which originally appeared on the official Ubisoft YouTube channel before being deleted, shows protagonist Aiden in search of a hacker. The latter character is under the control of an online player who is tasked with remaining hidden as he hacks in-game information of Aiden.
As was previously announced, Watch Dogs will also feature a companion app that allows the app-user to access a map-view of the game and aid the player during combat.
The game's hacking mechanics were featured during Late Night with Jimmy Fallon earlier in the week.
Update: A Ubisoft representative reached out to us to clarify that the footage is not a leak, but from a B-roll clip posted to their press site during E3. We apologize for the error in sourcing.