Tourists traveling to Mexico are often offered local tours at a lower-than-advertised price by O.P.C.’s (outside public contacts) which work for the timeshare organizations. You will see them located at booths or offices inside the malls or the airport.
They only request a minimal "deposit" and then indicate you have to pay the balance to the tour guide when the bus come to your hotel to pick you up.
The receipt is a little piece of paper with a telephone number that never answers and the bus never comes. Since the deposit was a minimal amount, most victims do not bother to make out an official report with the local authorities.
It is amazing just how many people are willing to give money to someone they have never seen before.