There are at least four bands that are named Cog. One from Australia, one from the Philippines, one from Croatia, and one from the USA.
These are photos from concerts where Cog played, so they may be of other bands that played the concert as well.
Big Day Out 2003 Jan 27, 2003 Ascot Vale, Victoria, Australia Uploaded by Womblingalong
Big Day Out Jan 19, 2003 Gold Coast, Queensland, Australia Uploaded by Martin S