Trisk

While you may be right, and it may not have been the smartest thing to do to join a large crowd of people as they headed someplace in Iraq....common sense and religion don't always mix well, and in Iraq (as well as many "dangerous" places in the middle east) there are many very, very religious people. If it is a requirement of a religion to go somewhere or do something, there are many people who would go, despite any risks that they may suspect could come up during the event.
Anyways, even before American troops came to this area, Iraq and much of the middle east was still in a similar position of danger. There are just way too many feuding religious groups scattered throughout the middle east and religious gatherings are a source of danger whether or not the area is in a "war-zone".
And it's not quite the same as your example with you, as a white boy, venturing into the ghettos of baltimore. Terror bombers tend to target areas with American troops and American supporters rather than their own religious events and places of worship. A better comparison would be you, as a black person, venturing into an area that is disputed as territory between two gangs. You wouldn't be out of place there, and may not even be a target there. But the area is dangerous and you may get caught in the cross-fire.

Still, the thing that popped to mind when I heard of this event is that this is true terrorism. Make people so terrified of what might happen that they kill each other, and you don't have to lift a finger.
For all we know, the rumor may have just been one terrified person voicing their fears and causing a panic. While the terrorists would still be responsible, in a way, because it was fear of them that caused this panic....it is likely that they actually had nothing to do with the event, and hadn't planned it at all.

It's really sad. But then again, I would say the same about many events going on there right now. This is just another drop of water in the bucket.