Customs and border protection officers have the legal authority to conduct searches of travelers to prevent the entry of prohibited items, though the intensity of these searches varies significantly based on suspicion and protocol. For the vast majority of international travelers, a "search" involves passing through a millimeter-wave body scanner or a metal detector, which identifies objects hidden under clothing without physical contact. However, if an officer has "reasonable suspicion" based on behavioral cues, travel patterns, or irregularities during the initial screening, they may perform a more intrusive pat-down search. In extreme cases where there is strong evidence of internal "body packing" of narcotics or other contraband, officers may detain a person for an X-ray or a clinical search at a medical facility. These advanced searches are relatively rare and are strictly governed by legal frameworks to balance national security with individual civil rights. In 2026, many airports have integrated "frictionless" biometric and AI-based scanning tech to identify anomalies faster, but the physical authority to search remains a core power of customs agencies worldwide.