Contraband cell phones threaten the safety and security of people who are incarcerated, correctional staff, and the public. They can facilitate violence and perpetuate underground economies. Contraband cell phones enter facilities through internal and external mechanisms; they can be brought in by facility staff, or they can be brought in by visitors, thrown over facility fences, or flown in on drones. This report reviews emerging technological strategies for detecting, disabling, and removing contraband cell phones.