Customer Proprietary Network Information, or CPNI, is information that telecommunications carriers collect about their customers during the normal course of providing service. Under Section 222 of the Telecommunications Act of 1996, carriers must protect this data and cannot share it without customer consent. CPNI includes call records, usage patterns, and real-time location data. The FCC fined AT&T $57.3 million and Verizon $46.9 million in 2024 for selling customers real-time location data to third-party aggregators who resold it to law enforcement and others without proper legal authorization.