Similar story, I was in Barcelona, and if you walk around the beach at night, you see dodgy-looking immigrants that will approach you and quietly ask if you want a cold beer.

See, it's illegal for stores to sell alcohol past a certain hour, so these guys provide a valuable service. However, I was with a friend who wanted to smoke some weed instead, so he went and asked one of the guys "do you have any weed?"

The guy looked horrified and quickly blurted out "No, no, only beer! You can't get that stuff!" before moving along.

It just struck me as funny that they would dodgily sell you illegal beer but that they would be righteously indignant at weed. "That, sir, is where I draw the line of illegality!"