This is one of the first one of these marches I've missed. I looked around and heard of no counter-protests planned. Their turnout was pitiful (there's another thread that gives 1500 as the crowd estimate). I just couldn't be bothered with these freaks today.
That was the Chronicle. They're there. I figure they'd know if anyone did.
http://www.freerepublic.com/focus/f-news/1774815/posts
Okay, I checked the Chronicle story and they've updated to three to five thousand. Still...in San Francisco...on a weekend...for an antiwar protest? That's sad.