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But 25 years later, the U.S. government is starting to ease some of the restrictions, which include measures that were tied to other attacks attempted in the months after 9/11.
Last year, the Department of Homeland Security, which was formed after the attacks, said flyers can leave their shoes on at airports, a major change for travelers going through regular security.
That rule was introduced after Richard Reid, who became known as the "shoe bomber," tried and failed to ignite explosive material in his shoe on a Paris-to-Miami flight in December 2001.
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New scanners installed at some airport checkpoints allow travelers to leave liquids in their bags before going through screening, though availability varies by airport and checkpoint. Limits on liquid container size remain in effect.
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"If you've got a few bucks, yeah, you can reduce the amount of screening and jump the line," Price said. "The other side of that is when you do become a member of PreCheck, you give up a lot more of your personal data to the government, and that's the trade-off. "
There's also a private option with Clear, with a shorter identification check line, in exchange for prescreened biometric data.
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Gate greetings return
TSA this week launched a free program allowing eligible trusted travelers, including TSA PreCheck members, to apply for access to secure gate areas without a boarding pass.
The program is called "Gateside," and the agency has rolled it out at 13 U.S. airports, including Dallas Fort Worth International Airport, Los Angeles International Airport, Detroit Metropolitan Wayne County Airport and Salt Lake City International Airport.
The area beyond TSA screening has been heavily restricted since 9/11. In launching the program, the agency said PreCheck members who use the program can "meet family members at their gate, join a friend on a long layover for lunch or dinner, visit airport dining and shopping locations, or greet service members returning from deployment. "
Participants must apply online one to three days in advance and receive approval before entering through security.
Privatization attempt
The TSA late last month scrapped a program it called TSA Gold+ that would provide privatized security at certain airports.
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TSA didn't respond to requests for further comment.
Tampa International Airport in Florida had reviewed the program starting in May, in part because it could shield the airport from the impact of government shutdowns, airport Chief Operating Officer John Tiliacos told reporters last month. Those shutdowns left TSA officers without regular paychecks for months, and staffing shortages led to long lines at airports around the country. The chance to add new technology was also a draw.
Tampa decided not to move forward with the program, and TSA announced its replacement shortly after. Tampa's Tiliacos told reporters last month "we weren't quite satisfied that we were getting all of the answers to our questions regarding the technology" and that drove the airport's decision to opt out.
Evolving threats
While some rules travelers have lived with for decades might be fading, the aviation sector is still dealing with changing threats.Gary Friedman | Los Angeles Times | Getty Images
As security technology evolves, so does the energy of potential attackers to overcome whatever obstacle they have and send their message.
Deterrents are important, but Jeffries said: "There is no such thing as the perfect security mousetrap. It doesn't exist. "
