I think we've all seen the picture of the man with the bags in front of the line of tanks. I'm on mobile, so you'll excuse me not linking something so famous.
To me, the fact that it's a still picture suggests that it was a moment of silent tension? I can't imagine what would have happened afterward. Unfortunately, I don't really know the back ground to it anyway, shop I don't know what happened politically afterward either.
Well, it is not a photograph but a still from a video. I remember watching this on the news. Here is the first 2 minutes, including the standoff and restart of the tanks: http://www.youtube.com/watch?v=YeFzeNAHEhU
I cannot source anything else so I will refrain from speculating who the guy was and what happened to him.
There is a lot of conjecture about Tank Man but there is very little hard data about this individual before or after the Tiananmen crackdown. PBS's Frontline did an episode about the event and its aftermath, including interviews with witnesses and specialists on China. It is well worth checking out as the documentary goes into great depth about the aftermath of Tiananmen and the legacy of this iconic image.