Police have issued a warning over gay dating app Grindr after a man was lured to a hook-up before being robbed and threatened with a cattle prod. CCTV pictures of two men wanted in connection with the attack have been released - and detectives fear the cuplrits may have targeted others. Scotland Yard said the man, 26, had been messaging another man through the popular online gay dating app Grindr and invited him round to his home in Bayswater, west London.