Bar massive Bill
This scam is quite famous near the Moulin Rouge area, there are small places in the streets near these places. You go to one of these small bars and you have a couple of drinks. Then some girls will join you and start to talk with you. When you decide to leave you to ask the bill and you will see something like 20 EUR for the drinks and 250 euros for "service fees" (the girls that you talk with). To avoid this stay away from these "underground" bars. If you are forced to pay you can your ass kicked and the best thing you can do is contact a friend and ask him to call the police. Is the best you can do.