The YouTube channel[1] was the starting point for the ARG providing 2 videos at game launch, one of which containing a Hex string that decoded to reveal a link to the first map file. A bulletin posted on the channel also provided an email address that responded with a second BSP map file.
Fake message.
Some users might have received emails from "ihavethetape". This is fake. (see picture)
Videos:[]
Clip094.mp4[]
Clip094.mp4
Clip095.mp4[]
This is the video in which the HeXD string can be found.
Clip095.mp4
Clip084.mp4[]
Clip084.mp4
In order to keep up to date with the ARG and see if any videos were released, it's highly recomended you subscribe to the channel itself: http://www.youtube.com/user/foundonthetape.