The official Assassin's Creed website has been tricked into revealing an October 29, 2013 release date for Assassin's Creed 4: Black Flag.
Visit assassinscreed.com and you'll be greeted with a four day countdown leading to a "world premier2 trailer". However, DarkZero discovered that by attaching a "v" to the end of the url you could trick the site into revealing more information - notably an October 29 release date and confirmation of the game's release on next generation consoles.
This exploit has since been removed, but you can see the results in the image above.
A full Assassin's Creed 4 reveal is coming on Monday.