The U.S. Federal Bureau of Investigation, or FBI, says the government's terrorist watch list of known or suspected terrorists has grown to one million entries.  The list - used by intelligence and law enforcement agencies to prevent terrorist acts - has been growing steadily since 2003 when the FBI set up a terrorism screening center to store, analyze and share information about suspected terrorists. While the list is touted by the FBI as an important counterterrorism tool, it has generated controversy and complaints.   

Caught in a security net

For some travelers, passing through airport security isn't easy. David Nelson says he is often detained at check points. "I said what do you mean, terrorist? Do I look like a terrorist," he asked. "I mean come on now."

Another man called David Nelson also has been routinely detained by security screeners. They are among hundreds of travelers named David Nelson who have been stopped because they are on the U.S. government's so-called "No Fly" list of known or suspected terrorists.

David Nelson says he is often detained by airport security

The list has been a source of frequent complaints by thousands of innocent travelers whose names have appeared on the list.

The No Fly list

The FBI says the No Fly list is a small part of the government's consolidated terrorist watch list, which is compiled mostly by intelligence and homeland security agencies.

All the information is managed and housed at the FBI's Terrorism Screening Center outside Washington. The agents gather and analyze information daily. They then pass it along to other law enforcement agencies.

"You want it (the watch list) to be accurate and complete. Complete is the key word because you do not want to miss anybody," said Tim Healy, the Center's acting director. "It is a balancing act between private citizens and their concerns and the safety of the United States and that is a balancing act that occurs everyday."

Tim Healy

Audit findings - watch list is growing

An audit by the Government Accountability Office found that the TSC's consolidated watch list has grown significantly from 288,000 entries in 2005 to a million entries in 2009, containing 400,000 names.

Authorities say the watch list is one tool used to reduce the terrorist threat. Its main purpose is to make sure individuals on the list are properly screened when they are stopped by police for traffic violations, or when people try to enter the country from international destinations. A call by police to the Terrorist Screening Center can quickly determine if the name on the list is a positive or negative match.

"We are involving state and local law enforcement in information sharing and we are involving other federal entities in information sharing of known and suspected terrorists, which is a good thing," Healy said.

Procedure to get names removed from list

But some say this government effort is flawed. Jay Stanley of the American Civil Liberties Union in Washington says the watch list violates citizens' rights. 

"Everybody agrees that Osama bin Laden and his henchmen should be on a terrorist watch list. We don't have a problem with that," Stanley said. "But the government needs to do this very carefully, they need to set up extremely strict procedures. Not only do they have to be very careful before you're put on the list but that you have the right to get off the list."

Jay Stanley

The Department of Homeland Security says 51,000 people have filed so-called "redress" requests since 2007, claiming they were wrongly put on the watch list.  

The FBI will not  disclose specifics of how the records or names on the list are generated.  But the FBI's Tim Healy says there is a procedure in place to get names removed. 

"If you have experienced an encounter when you are flying and you think you are on the watch list or even if they told you, you are on the watchlist there is a process you go through," he said. "The TSA  (Transportation Security Administration) will start going through their process and say is this guy actually watchlisted and what can we do to help this individual out."  

The FBI says 33,000 entries were deleted from the watch list last year based on outdated information and cleared investigations. And it says 95 percent of the people on the list are not US citizens. But Rachel Meeropol, a lawyer with the Center for Constitutional Rights in New York, says with a million entries the watch list has grown too big. 

"Whenever you cast a net that wide you are diffusing law enforcement resources from focusing on the individuals for whom there actually is evidence of a connection to terrorism," Meeropol said.  

As security at the nation's airports and on the borders has been tightened, the FBI defends the watch list as a valuable counterterrorism tool not just for the United States.

They say information from the list is also being shared with Canada, Australia and other US allies in the global effort to track down known or suspected terrorists.