Tag 'sites' automaticly added - but empty

If people upload a photo when they 'add site', the system automaticly (and hidden) creates a tag called 'sites'. It must be a tag for that photo because the tag is not displyed under tags for sites, but under tags for photos - but clicking that tag returns empty page. Such automatic tagging should not happend - and if it have to happen it should at least show some content if you click the tag.