Gatherings of people can be dangerous

We have a thing about people gathering together in places like Iraq, Yemen, Afghanistan, etc. We try to kill them. It doesn't matter if they're attending a wedding or a funeral. Someone determines that there is at least one bad person in the crowd, so it's okay to wipe out the crowd. Since the war on terror began, we have wiped out eight wedding parties killing about 300 people. Could all of them have been members of al-Qaeda?