There are at least six bands called "Weapon" (see below). The first band listed, from Alberta, Canada, owns the trademark for the name. As a result, the only other active Weapon as of 2012 (number 5, whose bio is listed below as Weapon 1980) have changed their name to Weapon UK in a settlement arrangement with the Canadian blackened death metal band WEAPON.
These are photos from concerts where Weapon played, so they may be of other bands that played the concert as well.
Marduk / 1349 / Withered / Weapon Jun 15, 2012 Seattle, Washington, United States Uploaded by Whiskey Echo Bravo