A report published by the Inspector General of the Department of Homeland Security in July 2009 said that "the No Fly and Selectee lists are intended to prevent specific categories of terrorists from boarding commercial aircraft or subject these terrorists to secondary screening prior to boarding, and are not for use as law enforcement or intelligence-gathering tools."
Following up in the 2009 DHS appropriation, TSA decided only to use the Selectee and No Fly lists -- not the full TSDB -- to screen passengers boarding planes. On Dec. 9, 2008, then-TSA Administrator Kip Hawley sent the mandated certification to the appropriations committees.
"No Fly and Selectee nominations to the TSDB are specifically made by the intelligence community to support aviation and national security," Hawley told the committee. "Another factor is that the TSDB includes records of persons who have been determined to not pose a threat to aviation or national security and are actively being monitored by law enforcement; overt scrutiny prior to boarding an aircraft could jeopardize the related terrorism investigation and would have a negative impact on overall security."
Besides, screening every "known or suspected" terrorist on the full watch list would inconvenience travelers, the TSA believed. "This practice would overburden the Secure Flight system and inconvenience a great number of travelers who are not the individuals identified in the TSDB," said Hawley.
Then, last Christmas, Umar Farouk Abdulmutallab boarded a Detroit-bound flight from Europe, wearing explosive underpants. He was on the TIDE list, but not the TSDB -- and thus not the Selectee or No Fly lists.
President Obama ordered national security agencies to re-examine the watch-listing standards. This summer, they made changes to the system. One of these, according to a counterintelligence official, is that they will now watch-list a person when they get terrorism-related derogatory information about that person from only a single source if they judge that the source is credible.
In Abdulmutallab's case, the single source who provided the lamentably ignored derogatory information happened to be his father.
Testifying before the House Judiciary Committee in March, TSC Director Timothy Healy also said that the government had reviewed the visa status of all known or suspected terrorists and discovered that there "were approximately 1,100 individuals that had received visas that were in the Terrorist Screening Center database."
"I believe most of those have been revoked. They are under review right now," Healy told the committee.
Still, as Americans pass through full-body scanners and pat downs this Christmas season, the inverted pyramid is still in place. Not all "known or suspected" terrorist are on the Selectee or No Fly lists, although those lists have grown.
Earlier this year, there were about 400,000 names on the full TSDB, 14,000 on the Selectee list and 4,000 on the No Fly list. Today, according to a counterterrorism official, there are about 420,000 on the full TSDB, about 18,000 on the Selectee list and less than 10,000 on the No Fly. Less than 5 percent of the people on the No Fly list are Americans.