Completely off topic - well nearly - there was a guy living down in Portsmouth a while back. He was a clog dancer and also wore street clogs with irons. Like most towns and cities the local feral yoofs were always abusing and mugging folks. Anyway one night said guy was walking down the main street when a gang of such yoofs approached looking for trouble. He hadn't a chance. But then the clogs-wearing-guy lifted one foot and brought it down on the pavement with an immense shower of sparks. In the olden days Northern kids old loved to do this but afterwards always got a bollocking from their parents for wearing out the soles. Reportedly the yoofs took off thinking that they'd met the devil.