The large audience even seemed to surprise some of the organizers, who did not have an overflow room available on site.
But now, it's come out that the packed room wasn't just filled with concerned citizens. Comcast paid shills to arrive early and save seats so that employees and other supporters could attend and cheer on executive vice president David Cohen.
The move came to light after the net neutrality advocacy group Free Press posted an MP3 file of an interview with an unidentified line-stander on its site.
"Honestly, I'm just getting paid to hold somebody's seat," a man said on the recording. "I don't even know what's going on."
Pictures also surfaced online showing audience members sleeping during the hearing.
Comcast Tuesday admitted to paying people to save seats for supporters, and also said it encouraged employees to attend. A Comcast representative also said it's common to employ people to stand in line and save seats at hearings in Washington.
The cable company also compared itself to Free Press which, it said, "engaged in a much more extensive campaign to lobby people to attend the hearing on its behalf."
But Free Press said there was a critical difference. "We didn't have to pay our people," said Associate Communications Director Jen Howard.
Free Press was part of a coalition of advocacy groups that filed the FCC complaint against Comcast that led to this week's hearing.
Last year, an investigation by The Associated Press revealed that Comcast was slowing traffic to peer-to-peer sites. Free Press and others then filed complaints charging Comcast with discriminating against particular types of applications, in violation of net neutrality principles.
Comcast responded that it's only trying to manage traffic on its network. Cohen told the FCC Monday that the slowing of traffic to peer-to-peer sites presents only a "virtually imperceptible effect on a very small number of users."
"There's nothing wrong with network management," Cohen said at the hearing. "Every broadband network is managed, and every network must be managed or no network would function."
The Harvard Law School classroom where the event took place could hold about 250 people. Some of the Comcast-employed place-holders remained in the room until the 2 p.m. lunch break, after which the crowd thinned out.
Separate from the FCC investigation, New York State Attorney General Andrew Cuomo also is probing Comcast. Cuomo recently subpoenaed information from the company about how it manages traffic.