Fax Cramming:
Crooks will take advantage of your perception that fax transmissions are inexpensive by inducing you to call fax numbers which are billable at high rates.  They would send requests to a company asking for information, which usually require pages and pages to be faxed back (of course at a premium rate cost).  For example, they will ask hotels and restaurants to fax menu and booking information.  Another example is a make-believe company phoning an estate agent, saying it is planning on relocating to the area and asking for its property lists to be faxed.