ABC is doing a Truther segment tonight:

Inside a 9/11 ‘Truther’ Convention

Chris Bury and producer Katie Hinman did just that this weekend — attending a convention in Valley Forge, Pennsylvania, alongside hundreds who share a collective distrust of the official explanation for the Sept. 11, 2001 attacks.

As they will report tonight, the attendees come from several different viewpoints, knitted together in this “movement” largely online.

We talk to conference organizer Betsy Metz, who tells us there is “absolutely a cover-up,” and the producers of “Loose Change” a conspiracy theorist film that is among the most downloaded videos in Google history.

Our presence was met, as you will see in tonight’s segment, with some resistance. For obvious reasons, the “truther” movement has clashed with many in the mainstream media.

John Patrick Bedell, the gunman killed in last week’s Pentagon shooting, had previously posted comments online that questioned what really happened in 2001. Those at the convention disavowed Bedell’s act of violence.