By Benedict Tetzlaff-Deas Shocking footage shows the moment a man is Tasered by police on a bus after threatening other passengers with an “unknown substance”. Officers stormed the vehicle in Croydon following a three-hour stand-off on Sunday evening. The man – reported to be in his late 30s – reportedly became aggressive when he was asked to stop smoking. Footage shows the group of officers in blue jumpsuits entering the mostly empty double-decker bus while holding shields aloft. Police then proceed to the top deck where they quickly move in on the man, crowding him with the shields while one…