My friend's 23 year old daughter Alice went to London, England for a 10 day vacation recently. She is an American college girl and had never been to England before. She was staying in London, seeing all the sites and enjoying herself. Well one day she was walking somewhere in London and waiting to cross a busy street. She was by herself. It was about 1:00PM or sometime in the early afternoon.

This man who she described as a West Indian man with a turban started making small talk with her before crossing the road. Many other people around but the man started talking to my friend's daughter. He wanted to read her palm or something to that effect. Alice didn't want to be rude so she just talked to him for a minute or two. He didn't actually do a palm reading but whatever he told her, he then told her she had to pay him 20 pounds!! He did not do a palm reading. They were just standing at the corner waiting to cross a busy road. He then told her she should go to a ATM to get some money out to give to him. I'm not sure if he even actually looked at her palm or not.

He said if she didn't give him the money he wanted that something terrible would happen to her plane on the way back to America. Crash or something terrible.
She got scared and went into some shop near where they were talking.
I guess the man took off walking away fast. She never gave him money but it scared her.
She came home safely the other day and is ok.

Is this a common practice in London or maybe other large cities in UK?
Are the police trying to stop this? Are they using this scam and telling people on a street corner that they will read your palm and demand money?