PHILADELPHIA (CBS)—The FBI is again warning college students across the country about a credit card scheme that targets classmates and their campus bookstore.

The investigation began when a number of universities reported last spring that their bookstores lost thousands of dollars in purchases that were made with stolen credit card information.

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The FBI says in each of the cases: perpetrators claiming to have lost their student ID cards enlisted unwitting students to essentially vouch for them at the counter with their valid IDs. The perpetrators then made their purchases—in many cases, high-end electronic products—with a bogus credit card that matched their bogus identification.

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“Students are being used to facilitate this activity,” said FBI Special Agent Jennifer Gant, who manages the Bureau’s Campus Liaison Program, which started in 2008 to help improve communications between the FBI and U.S. colleges and universities. The program originated in the FBI’s Counterterrorism Division as a way to build relationships and increase two-way information sharing before a crisis. Each of the Bureau’s 56 field offices has a special agent or task force officer whose duties include building and maintaining connections with school leaders and campus police in their regions.

Investigators believe campus bookstores may be targets for this scheme because they generally offer specific discounts for students, who may not see anything wrong with helping out an unlucky stranger claiming to be a classmate.

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The FBI offers these tips on how to protect against the scam:

  • For students, don’t agree to facilitate a purchase for someone who does not have a valid student ID.
  • For school administrators, establish a procedure at your campus bookstore that includes a provision against allowing a purchaser to use a credit card in someone else’s name.
  • For victims, notify campus police or campus public safety.