TSA Rules to Fly By

Air travel in the United States is busier than ever, with the Transportation Security Administration (TSA) screening over 858 million passengers in 2023 alone. For each of these travelers, airport security rules dictate what they pack, what identification they carry, and even whether shoes must come off at checkpoints. But more than two decades after post-9/11 security measures transformed the flying experience, some of these requirements are beginning to ease. In July 2025, federal officials ended the rule that passengers must take off their shoes at TSA checkpoints, and they have hinted that longstanding liquids limits could soon be relaxed thanks to new screening technology.

U.S. airport security is anchored in federal law and overseen by the Department of Homeland Security. In response to 9/11, Congress created the TSA to assume responsibility for screening airline passengers, replacing the patchwork of private screeners that had staffed checkpoints before 2001. TSA regulations require all passengers and bags be screened before boarding, and prohibit items deemed dangerous—including weapons and oversized liquid containers—in carry-ons. Violators of these rules face stiff penalties. Federal mandates continue to evolve: Beginning in May 2025, U.S. travelers must present a REAL ID-compliant driver’s license or other approved form of identification to board domestic flights.

Not every security measure is one-size-fits-all. Voluntary Trusted Traveler Programs and other new technologies streamline screening for passengers willing to undergo upfront government vetting. For instance, TSA PreCheck—now with more than 20 million members—allows pre-approved travelers to use expedited lanes where liquids and laptops may stay in bags. Similar programs, such as CLEAR’s biometric identification and Global Entry for international arrivals, reflect a shift toward risk-based security, which tailors screening intensity to a passenger’s assessed risk. By encouraging travelers to share information and pass background checks in exchange for a less intrusive airport experience, these programs allow TSA to focus its resources on higher-risk passengers.

As airport security adapts to evolving threats and new technologies, scholars and policymakers continue to debate the appropriate scope of airport regulations. Supporters credit stringent TSA protocols with maintaining aviation safety, albeit at the cost of convenience. Critics, however, question whether certain rules have outlived their usefulness or infringe on the privacy of travelers.

The TSA’s push to incorporate facial recognition cameras at airport security checkpoints exemplifies this tension. Privacy advocates and lawmakers warn that routine biometric ID checks could create a “national surveillance state,” noting that many travelers may not even realize they can opt out of the face scans. Industry groups and security officials counter that facial recognition and other innovations are vital for efficiency—speeding identity verification and reducing lines—so long as their use remains voluntary and transparent.

In this week’s Saturday Seminar, experts discuss modern airport passenger regulations—what is required, what is optional, and what is changing in the quest to keep flying both safe and traveler-friendly.

• In a report from the Congressional Research Service, Bart Elias and several coauthors discuss whether and, if so, how to expand risk-based passenger screening to strengthen aviation security while protecting civil liberties. The Elias team describes the TSA PreCheck regulatory framework—including background checks, expedited lanes, enrollment targets, vendor participation, and fee recovery—as a policy tool to improve efficiency while maintaining security. Elias and his coauthors emphasize that future policy choices must weigh efficiency gains against privacy concerns and the costs of expansion. The Elias team further notes that private sector partnerships could make the PreCheck program more accessible and affordable.
• The TSA’s growing use of facial recognition technology raises pressing questions at the intersection of technology policy and civil liberties, argues McKenly Redmon of Southern Methodist University Dedman School of Law in an article in the SMU Science and Technology Law Review. Redmon highlights accounts of travelers alleging they were not informed of their right to opt out, citing inadequate signage and TSA agents misrepresenting the program’s voluntary nature. Redmon also emphasizes that facial recognition can be inaccurate and poses disproportionate risks of misidentification for certain ethnic groups, causing bias and traveler hardship. When deploying facial recognition technologies, Redmon concludes, the TSA must weigh safety and efficiency benefits against potential harms to civil liberties.
• In a report from the Privacy and Civil Liberties Oversight Board, Beth Williams of the George Washington University Law School and several coauthors argue that the TSA’s facial recognition program should remain voluntary, allowing travelers to opt out without penalty, such as being routed to longer lines. The Williams team urges the TSA to standardize signage and staff training, as well as to investigate and resolve problems travelers experience with facial recognition. Williams and her coauthors also recommend publishing usage and performance metrics—including opt-out rates, false negatives, and impostor detections—and reporting demographic performance while protecting privacy.
• In an article in the Vanderbilt Journal of Entertainment & Technology Law, Robert Lowell of Vanderbilt University School of Law examines the TSA’s expanding use of facial recognition to screen travelers. Lowell argues that the TSA’s adoption of facial recognition technologies raises not only serious privacy concerns but also underlying questions about the agency’s authority to use this technology absent clear congressional guidelines. Lowell highlights the technology’s ability to capture invasive images and the lack of transparency in how the images are used. Although U.S. citizens can currently opt out, Lowell notes, the TSA has indicated participation may become mandatory. Lowell urges Congress to set explicit limits on facial recognition technology to protect U.S. citizens’ privacy.
• The border search exception to the Fourth Amendment should not automatically apply to electronic devices, argues Philetus Holt of Fordham University Law School in an article. Holt explains that the Fourth Amendment permits government officials to conduct warrantless searches at U.S. borders and airports, justified by the government’s interest in border security and travelers’ reduced expectations of privacy. He notes, however, that electronic devices contain vast amounts of personal data, making their search less reasonable under this exception. Holt reviews how courts distinguish between routine manual inspections and more intrusive forensic examinations, with some circuits requiring reasonable suspicion for the latter. Holt proposes a new legal framework that balances national security with travelers’ heightened privacy interests in their digital information.
• Individuals of broadly Islamic and Middle Eastern heritage are overrepresented in the recently leaked No-Fly List compared with other Americans involved in violent acts, finds Matteo Garofalo of the University of Maryland Francis King Carey School of Law in an article. Using names as a proxy for ethnoreligious origin, Garofalo analyzes the No-Fly List. He concludes that the overrepresentation of Islamic and Middle Eastern people supports longstanding critiques of the No-Fly List as discriminatory. Garofalo finds that terrorist attacks by Islamic and Middle Eastern people are more lethal on average than those committed by others in the U.S., but argues that this difference does not justify their overrepresentation. Garofalo recommends that his findings inform future anti-terrorism policy.