Search the Internet for the name John Lynn and you may find a roofing contractor from New Mexico, an artist from England, a film professor from Florida and dozens of other people who share the name.

You may also find a retired airline pilot and former military officer from Carlsbad, who said he recently found out his name somehow ended up on an airline-passenger watch-list run by the Department of Homeland Security.

After the Sept. 11, 2001, terrorist attacks, the government created lists of people who were either barred from flying or who called for extra scrutiny before being allowed to board airplanes.

Critics, including the American Civil Liberties Union, say the government doesn't provide enough information about the people on the lists, so innocent passengers are often caught up in the security sweep if they happen to have the same name as someone listed.

Lynn, a retired Navy lieutenant commander, said his efforts to clear his name from the list have been fruitless and frustrating.

"I find it totally un-American; there's no due process," the 75-year-old Carlsbad resident said. "You're left with no information on how or what caused you to be put on the list and no redress."

Government officials say that despite the problems they cause, the lists are essential to keeping passengers safe. They have also created a program to help address some of the public's concerns.

Last year, the Department of Homeland Security announced the Traveler Redress Inquiry Program to help passengers who were denied or delayed airline boarding.

The program allows passengers to submit personal information that is supposed to help identify them to authorities.

"This is a win-win program," Department of Homeland Security Michael Chertoff said when he announced the program. "Eliminating false positives makes the travel experience more pleasant for legitimate visitors and frees up our front-line personnel to apply even greater scrutiny of those who truly present safety and security risks."

Officials with the Traveler Redress Inquiry Program could not be reached for comment.

But the program has not satisfied Lynn. A former columnist for The Californian, the Southwest Riverside County edition of the North County Times, Lynn said the first sign of trouble appeared when he made travel arrangements to visit his daughter in Texas last summer.

When he booked a flight via the Internet, he found out he couldn't get boarding passes online. He had to go to the ticket counter.

Lynn said he didn't think much of it at the time, believing that there might have been a system failure or some other problem.

In October, he and his wife wanted to fly to Portland, Ore., when the ticket agent at the airport told him he was on a passenger watch-list. He was given a form to fill out and was allowed to fly.

It was a minor inconvenience, but Lynn said he was bothered by the secrecy of how his name ended up on the list in the first place. He also did not like the reply he received from the Traveler Redress Inquiry Program.

A form letter dated Nov. 29, 2007, said: "Where it was determined that a correction to records was warranted, these records were modified."

The letter also said the agency could not guarantee Lynn would avoid future delays or "the need to go to the ticket counter to obtain a boarding pass."

It did not address his main concern, Lynn said.

"If they are going to put you on a list, they need to tell you the reason for it," he said.

The ACLU and other groups critical of the passenger watch lists say Lynn is not alone.

"As of now, he may never know," said Reggie Shuford, a senior staff attorney with the ACLU in New York, who filed one of the two lawsuits his group has filed addressing the watch lists.

What started out as a list containing the names of a few hundred known terrorists turned into more than a dozen lists from agencies ranging from the IRS to the FBI containing thousands of names of people who are wanted by those agencies.

Kareem Shora, executive director of the American-Arab Anti-Discrimination Committee, an advocacy group for Arab-American rights, said once a name is on the list there is no guarantee it can be removed.

"It's hit and miss," Shora said. "We've heard from a few people that say they are no longer inconvenienced. They are no longer delayed two hours. And others have not heard back."

Although there have been concerns about whether people of Middle Eastern descent were being profiled, Shora said his group does not believe the watch lists discriminate against people based on their ethnicity or religious background.

However, there are other problems with the lists, including errors, inaccuracies and inconsistencies, critics say.

A Justice Department report released last year that examined the Terror Screening Center, which maintains a consolidated list, said it contained more than 700,000 records.

Shora and others say there is value in having a passenger watch-list, but the program needs to be revamped.

"The real question is, 'How can you find the needle when the haystack continues to grow?' " Shora said.

Contact staff writer Edward Sifuentes at (760) 740-3511 or esifuentes@nctimes.com.