Here's the situation. Kerry is speaking in Florida. Young guy asks him a series of questions ("Why did you cede to Bush when there were reported voting irregularities?" "Why not impeach Bush before he invades Iran?" "Were you a member of skull and bones at Yale?"). It could be that there is more to the story, but it appears to be a typical open forum kind of impassioned, somewhat rambling sort of speech, sort of question.
This video captures what happened next. The police forcibly escort him away from the microphone and then taser him at the back of the hall. Kerry shows why he lost the election by demonstrating an apparent ignorance of what is going on to the very guy who just asked him a question - at the least demonstrating the tone deaf approach that left even his biggest supporters feeling fairly ambiguous about his candidacy. (If Bush goes down in history as the worst president, what will that say of Kerry's candidacy?)
I blame this in part on the now mindless competition to get tough on crime. We've hired a ton of police officers and they, quite simply, don't have a lot to do. The trivial becomes a big deal and even a guy at a microphone attracts a half dozen police officers.
A part of me is fairly incensed at a society that has become this intolerant of speech and this tolerant of arrests for no good reason. (The guy hollers at one point, before being tasered, that they don't need to arrest him because he'll walk out of there.) But a part of me is delighted to be living in this age of YouTube. As the public sector is made more public - as even arrests are subject to the review and scrutiny of the general public - this kind of nonsense will have to wane. And that's good news.