By the fuzz.. Yep a few times, all a long time ago;

Camden Underground - I was walking through with a homemade lung and a fair lump of weed when 'oh shit, a sniffer dog' - luckily the policeman handling him was distracted by someone else - got away by petting the dog and pretending he was interested in me because i was petting him.. 'The dog's working son'

Reading Festival - no one was playing so we were all sitting around the campsite, I'd rolled an oversized spliff and had been smoking for a few mins, about to pass when two cops walked into camp. I'd caught sight of them and put the spliff under my boot.. Then had to chat to them acting fine 'no officer, not smelt anything funny, what was it?' as the weed kicked in properly hard.

Another time I was hanging out with my girlfriend, smoking in this car park when a police car rolled in (we then realised we were sitting right in front of a camera) - i mimed slinging mybweed in the river and we got up and started walking away, guess the police figure 'mission accomplished' as they turned the car around and left.