For nearly two decades, commencing shortly after the advent of commercial cellular telephone service in the United States, federal law enforcement officers have had the authority, subject to court approval, to conduct "roving" wiretaps and electronic surveillance on persons suspected of committing federal crimes. A roving wiretap, also called a "multipoint" tap, attaches to a particular subject who utilizes multiple telephones or communications devices, rather than to a particular telephone or device, as in the case of a conventional wiretap. A roving wiretap, therefore, allows law enforcement officers to "follow" a subject and lawfully intercept that person’s communications with a single court order when the person’s telephone (or other communications device) is subject to change, e.g., because he or she is moving from phone to phone to thwart (or with the effect of thwarting) detection, regardless of the phone used when communicating.
