The operator of a Marathon gas station in Cicero, Ill., near Chicago, reportedly told police this week that two men had climbed onto the roof of the station and placed aluminum foil around an antenna that transmits payment card transaction data. According to media reports, the two men, in their 20s, had entered the station at around 5:15 p.m. on Tuesday and tried to make a purchase with a credit card. When the card did not work, the men asked the operator to authorize the transaction manually, reports say. The operator refused and, after the men left, checked a surveillance tape that showed the men climbing the roof and covering the antenna with foil. Police reportedly have not identified the two men. CardLine could not reach the gas station operator for comment today. Gartner Group LLC analyst Avivah Litan tells CardLine she has not heard of similar uses of foil in card fraud attempts. But she says protecting card acceptance infrastructure is an important but difficult task at many service stations. "When people attack gas stations, it's usually because of old technology" such as outdated, insecure card-acceptance terminals on fuel pumps, Litan says. "And it's because there's only one attendant, who can't pay attention to what's going on."