The Webflyer points to a great David Rowell column, including:
An argument ensued. Ms O’Leary not unreasonably thought it unfair to be trapped on the delayed flight when there was another flight due to leave shortly that she could make if allowed to leave the United Express flight. The pilot called the police who arrested her for disorderly behavior. After some three hours of questioning by police and FBI, they eventually released her.
Ms O’Leary is not only a former US Secretary of Energy, but also a current board member of United Airlines, and has been for almost five years.
Now, while I agree that you can’t trust those senior government officials on anything, I can’t see three hours of questioning. The airlines are clearly using the police to threaten passengers who think their service stinks, and are speaking out.