Using Craigslist to commit armed robbery. Police say 27-year-old Eli Robertson and two other man used the popular social media site Craigslist to advertise a cell phone for sale. The persons who responded were to meet them at a motel on Tamiami Trail to make the purchase. But when the buyers showed up, investigators say they were robbed at gunpoint. Detectives say they were able to trace both a cell phone number and an Internet I-P address to an address occupied by Robertson and two other men. Both of them have already been nabbed in the case.