I hope you don't mind if I share my experience with you:
My wife and I were spent some of our Honeymoon in Barcelona. On our last night, we decided to see the Fountain/Light show at Montjuic. Walked out of the hotel headed for the Metro and then a guy approaches us. He had an Eastern European accent, and asking us to point out in his map our current location cus he had no idea where he was. We've been staying in Barcelona for a week, and knew the area a little bit, so we decided to help. Then all of a sudden, two older fellas approach us, locals, in civilian clothing. Claims they are undercover officers, flashes us with their IDs ( too fast for me to even see the pictures, let alone read their names on it). Then questions the Eastern Euro guy and they tell all 3 of us that they are looking for drug dealers. Euro Guy freaks out, they ask for his ID, he shows it to them, and they look over it, and then hand it back and tells him to scram, and he runs away, kinda shaken up. The officers then turn to me and my wife, ask us for our IDs and wallets, we comply. Understand that we were on the very last part of our honeymoon, so we were pretty much broke, and probably had a couple of euros in our wallets. The guys sniff the wallets, and then gives it back to us and lets us go. Me and my wife look at each other, then kept walking to the metro and enjoyed the fountain show.
Up to today, we can't figure out what was going on that night. We have our own theories on who was the bad guy, or which party was the hustler.
Any of you experience any similar situations while in the City? Got any suggestions/theories on what was happening? Somebody wanted to hustle us that night, but they probably picked the poorest tourist couple in the area lol.
PS. Found this site after browsing the web looking to discuss today's 5-0 annihilation of Madrid. Congrats!