The "tea house scammer" ask me yesterday in shanghai at the bund. It was a boy and a girl, I think they was 20 to 25. Their english was very poor, but after a short conversation they ask me if I like to drink tea and they could bring me to a tea house. I refuse that.
Then they want to bring me to the sightseeing tunnel, maybe they can ear some money with this, too? I refused again and walked away.