http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/08/25/ DDGC1EBVL41.DTL

Hair-raising tale. Reminds me of a time when I was a kid, and blundered into an anti-american demonstration... (I think it was that same trip I wandered off down the river and got lost, remember Andi? We made cloisonne teacups, or something?) You get trapped on all four sides by people, and you have the awful feeling that if you stumble that you'd be trampled to death. Read it.