Updated

The number of people the FBI targeted with national security letters more than doubled last year to more than 14,000.

The letters enable the bureau to collect virtually unlimited kinds of sensitive, private information like financial and phone records in terrorism and espionage investigations. In 2007, the Justice Department's inspector general found widespread violations in the FBI's use of the letters, including demands without proper authorization and information obtained in non-emergency circumstances. The FBI has tightened oversight of the system.

The letters are controversial because there is no court scrutiny of the process; the letters are simply signed by FBI officials without review by a judge.

In a summary to Congress, the Justice Department said the FBI made 24,287 national security letter requests last year for information regarding 14,212 people. That's up from 2009 when there were 14,788 requests for information about 6,114 people.

In 2008, the number of national security letter requests was 24,744 and involved 7,225 people.

Last year's increase from 2009 levels, however, comes nowhere near the activity in national security letters that took place in the years immediately after the Sept. 11, 2001, terrorist attacks.

From 2003 to 2005, the FBI reported issuing 143,074 national security letters requesting customer data from businesses. In 2007, the Justice Department's inspector general said that number did not include an additional 8,850 requests that were never recorded in the FBI's database.

The Justice Department summary to Congress for 2010 also reported that the government:

— Filed 1,579 applications with the secretive Foreign Intelligence Surveillance Court to conduct electronic surveillance or physical searches, up from 1,376 applications in 2009, but down from 2,082 in 2008.

— Made 96 applications to the surveillance court for access to business records, up from 21 applications in 2009.