I thought my local periptero had been selling me dodgy fags over the last few days. I had noticed that the cigarettes would burn down to a particular point and then go out! I thought it was either a dodgy batch or they were counterfeit. So I had a moan in my periptero this morning and was told that they all do that now so that when someone in car chucks his fag end out of the window it will go out! This was confirmed by some of the other patrons in there at the time.
You learn something new every day!