Scott Cornell, national manager of a special investigation group focusing on supply chain security at the insurance company Travelers, said the thieves take advantage of the Internet, which allows them to do "so many things online where nobody sees you," including setting up a company and bidding on loads.Within a few years, Lewis said, identity theft-related scams are expected to become the most prevalent method of cargo theft. Experienced thieves know where the major manufacturers are located. And some are savvy enough to pick out which brand of electronics or appliances to steal by bidding on loads posted online. Someone wanting to steal a truckload of copper, for instance, would target shipments coming out of Carrollton, Ga., where a major copper-wire manufacturer is located. Food and beverages were the most commonly stolen items, accounting for 23 percent of all thefts last year, followed by metals at 16 percent, and electronics and household goods at 12 percent each. Other products made up the remaining 37 percent, including pharmaceuticals at 3 percent, according to CargoNet's 2012 report. One reason food shipments are popular targets is because they have a lower value than electronics or pharmaceuticals, which are often more heavily protected. Plus, food generally does not have any serial numbers to trace. The loads are also difficult to recover. Companies often do not know they have been scammed until their shipments fail to show up, usually four to five days after they were stolen, Coughlin said. By that time, the goods have probably already been sold on the black market. The trucking and insurance industries are fighting back, urging freight brokers to take extra precautions, such as checking information before awarding shipping contracts to unfamiliar truckers. The California Farm Bureau Federation warns about clues that could indicate a suspicious hauler: temporary name placards or identification numbers on the truck, abrupt changes in the time of the pickup and lack of a GPS tracking system on the truck.