To my suprise, they're denying any explicit support for the legislation:
http://cloud.github.com/downloads/duncan-bayne/duncan-bayne.github.com/Email%20Response.pdf
... and they don't appear on the official list of supporters here:
http://judiciary.house.gov/issues/issues_RogueWebsites.html
However, they do appear on this list:
https://docs.google.com/spreadsheet/ccc?key=0AmGJz_37ojoqdFZhYlBhN2hQOGRoN2R0ZGh3VDZlblE&pli=1#gid=0
... and many others like it.
Could someone familiar with this issue please explain the apparent discrepancy?