@creitve some commons schemes:

1. Post a fake flat which is very appealing. Good loc, good price, good furniture, etc. Receive many calls, don't answer them, collect a base of clients looking for a flat. Call them.

2. Take money for something, do not do that something. For example, receive payment for reservation and disappear.

3. Offer flats without having legal rights to do so.

They all take your money and time.