While TSA’s primary mission is to detect threats to aviation security (such as explosives and weapons), their advanced X-ray scanners and high-resolution CT technology are highly effective at identifying organic materials, which includes cannabis. A single joint is small, but it can still be flagged during a search for other items like electronics or liquids. TSA's official policy is that they do not actively "hunt" for drugs; however, if an officer discovers marijuana during the routine screening process, they are federally mandated to report it to local law enforcement. What happens next depends entirely on the jurisdiction of the airport. In "legal" states like California or Illinois, local police may simply ask you to dispose of it or take it back to your car. In prohibition states, you could face confiscation, citations, or even arrest. Because airports are subject to federal law where cannabis remains illegal, the safest course of action is to leave it at home to avoid potential delays or legal complications that could ruin your travel plans.