"Public Enemy Number One" is a term used to describe an individual or group that is considered the most wanted or dangerous by law enforcement. This label often signifies a person involved in serious criminal activities, such as drug trafficking or violent crimes, and is typically associated with high-profile cases that attract media attention. In the United States, the term gained prominence during the 1930s, particularly with the FBI's focus on notorious criminals like John Dillinger and Al Capone. The designation serves to inform the public about threats to safety and encourages cooperation with law enforcement in apprehending these individuals.