The FBI underreported how often it used the USA Patriot Act to force businesses to turn over customer information in suspected terrorism cases, according to a Justice Department audit.
One government official familiar with the report said shoddy bookkeeping and records management led to the problems. The FBI agents appeared to be overwhelmed by the volume of demands for information over a two-year period, the official said.
"They lost track," said the official who like others interviewed late Thursday spoke on condition of anonymity because the report was not being released until Friday.
The FBI in 2005 reported to Congress that its agents had delivered a total of 9,254 national security letters seeking e-mail, telephone or financial information on 3,501 US citizens and legal residents over the previous two years.