Posing as staff from a construction firm, members of the US Government Accountability Office (GAO) asked the Nuclear Regulatory Commission (NRC) for a licence to purchase small amounts of substances such as caesium-137, which is found in moisture meters used on building sites.

Four weeks later, without running detailed checks on the company or requesting a visit, the NRC issued the license. The GAO staff then altered the license to indicate they had NRC approval to purchase unlimited amounts of radioactive material. Suppliers of such material accepted faxed copies of the doctored license and even offered discounts for purchasing larger quantities.