[mabelkitty]

But why would they plan terrorist attacks on Americans?

Would they do this so they can say Pro-Troop supporters did it?

Now I don't believe that for one second. Not in the fine city of San Francisco.

[JoeSixPack1]

But why would they plan terrorist attacks on Americans?

They don't plan much of anything except anarchy. That's what anarchists do.
Unrest created by anyone for any reason is considered a plus to their cause. And to have a secondary cause as unimportant to them as this war with Iraq is, it's a welcome opportunity to create as much anarchy as possible and pass it off as a war protest.
Of course by the time the anarchists are in full swing, the real peace freaks have safely slithered back into the sewers.