Today within 30 minutes two hackers went no clipping through multiple houses in our area. These two videos show Gabe Newell and Player who were playing on US East II walking through walls.
I expect these people to be banned as they, and others, are making the game unplayable.
Gabe Newell - http://www.youtube.com/watch?v=3Y0O_mzdsy0
(User was banned for this post ("missed the hackers report thread" - postal))