Obviously there are plenty of people who aren't using the Content ID system and are sending in traditional DMCA requests, but I imagine that the automated system takes care of a big chunk of the work.
http://en.wikipedia.org/wiki/Online_Copyright_Infringement_L...
This is why Justin.tv can go on when its top channels are obviously illegal. It has to receive notice as such instead of simply monitoring what's currently broadcast and killing things like football.
TITLE II--ADDITIONAL ENHANCEMENTS TO COMBAT INTELLECTUAL PROPERTY THEFT
http://thomas.loc.gov/cgi-bin/query/F?c112:1:./temp/~c112Ggu...:
PS: You replied several days after that post, but on the off chance you see this, I figured why not respond.