When the actual participants later showed up, the seat warmers left, as per the terms of their agreement.

Not true. I was there. I did not see any of the paid seatwarmers leave before lunchtime. During the entire first panel (11-2) there were over 100 people who had taken the day off work, students, etc. who care about issues of net neutrality and who were barred from entering. I didn't see people start to leave at all until around noon, and then it was a scattered handful of folks who had to get back to work after lunch, etc., not the seated-together block of Comcast plants.

It's one thing to pay someone to stand in a line for you. I think it's icky, but I'm aware it's common practice for federal hearings in DC, etc. It's completely another to pay people to sit in a seat and cheer when they have zero interest in the issue. Some of those folks didn't even know what wi-fi was, and freely admitted they were just paid to be there.

Free Press and other organizations put out notices and though what (from the outside) looks to be a lot of hard work and community-building, organized a grassroots base to attend the hearing. Comcast didn't do that, they took the easy route and hired people to get there house ahead of time.

I was there as well. The FCC commissioners, thankfully, were not fooled - the seatwarmers were rather transparent, sitting together, clearly not engaged, and all clapping in unison and often after a slight delay. When the bused-in folks all left at the lunch break, the room was filled for the second panel with more ordinary people who actually cared about the issues. Even in the stacked first panel, pro-net-neutrality folks were more present - many of us standing and sitting on the floor - than the industry likely expected. (Some of us know the venue and snuck in.)

Also - just got this link from Free Press - Apparently Comcast admits to hiring line-holders but not seatwarmers:
http://www.portfolio.com/news-markets/top-5/2008/02/26/Comcast-FCC-Hearing-Strategy