The panel was called "Marxism and Beyond." There is a write-up here in this post (http://littlebutfierce.livejournal.com/410138.html), which includes the Audience Member.

Basically, he sat in the front row and kept his hand raised for the entire panel, pretty much raising it immediately after being called on to say something. wrdnrd (the moderator of the panel) kept saying that she saw him and would get to questions at the end of the panel, but sometimes he just started talking without even getting called on. He even wrote a note on a piece of paper and put it up on to the table, giving it to a panelist.

People in the audience told me that before the panel began, he was loudly talking about how he likes "arguing with Marxists," which was curious as nobody on the panel was a Marxist - hence the title, "Marxism and beyond."

What made troubleinchina leave in anger was the point toward the end of the panel (after he had made an annoyance of himself) when wrdnrd made it explicitly clear that they would take questions only, and not comments. Ignoring this request, he started waxing on and NOT asking a question. He was talking about opinion polls in the United States, in which just about everyone tends to answer, "I'm middle/working class!" even when they're not. He said that "the United States has its own special relationship to race and class." Another audience member was like, "Dude, that's American exceptionalism, stop it right now," and he kept talking. At some point, I snapped, "I would really like to hear a QUESTION," and the he was all acidly, "Yeah, yeah," and waved his hand in a pshaw-way, and didn't talk again.