U.S. enforcement and intelligence officials said Wednesday that the no-fly list barring passengers with suspected terror ties from boarding planes has already increased in size since the attempted Christmas Day bombing of Northwest Flight 253, and was likely to get much larger.
"It's getting bigger and it will get much bigger," said Russell Travers, deputy director of the National Counterterrorism Center, testifying at a hearing of the Senate Homeland Security Committee.
After the hearing, government officials confirmed to ABC News an earlier press report that the no-fly list had nearly doubled in size since December 25, from 3,400 names to over 6,000 individuals.
"The figure reported today generally reflects that expansion, although the number of individuals on the no-fly list varies daily," said an official from the FBI's Terrorist Screening Center (TSC).
In the wake of the attempted bombing of Northwest 253, President Obama ordered a review of the country's watchlisting procedures after it was discovered that suspect Umar Farouk Abdulmutallab was in a vast terrorism database called the Terrorist Identities Datamart Environment (TIDE), but had not been flagged for the no-fly or the larger watchlist by U.S. officials.
"This was not a failure to collect information, and, unlike the missteps leading up to 9/11, it was not a failure to share it," said committee chairman Sen. Joseph Lieberman, I.-Conn., at Wednesday's hearing.
After the attempted attack, said TSC Director Tim Healey at the hearing, TSC undertook a review of the no-fly list and reviewed several other watchlist databases to "ascertain the current visa status of all known and suspected terrorists, beginning with the no-fly list."
"The TSC has made some temporary and limited additions to the watchlist to counter the specific terrorist threat observed on December 25, 2009," said Healy. "As a result, a threat-related target group was identified and individuals from specific high-threat countries…to prevent future attacks."
The NCTC's Travers, who oversees the TIDE database and watchlist nomination process for NCTC, told the committee, "We are enhancing the ability of individuals to put people on the lists."
One issue for agents and analysts is dealing with the massive volume of data collected by the intelligence community on a daily basis.
"Every day approximately plus or minus 10,000 names are coming into the terorrist identities analytic community," Travers said. "The size of my Monday morning read book when I walked in: 842 pages, 1,520 pieces of information."
The watchlist and no-fly list has been sharply criticized over the years. Small children have been selected for screening, and the late Sen. Ted Kennedy was on the no-fly list for a time due to confusion with an IRA suspect who may have shared a name or alias with the Senator.
In January Congressional testimony, NCTC Director Michael Leiter said that in the years since 9/11, the pendulum had swung away from watchlisting individuals, "The pressure was in the exact opposite direction…to remove and clean up the watchlist and reduce the amount of inconvenience. Now we are going in the other direction."
"That is a bit of a sea-change since December 25," testified Travers Wednesday. "I've been doing this now for several years and I will say I'm 100 percent certain I never had anybody tell me the list was too small before Christmas."
During Wednesday's hearing Lieberman said that security concerns outweighed any privacy concerns. "I don't want to diminish the privacy concerns," said Lieberman, "but one mistake and people get killed."