A federal appeals court rejected T-Mobile's attempt to overturn $92 million in fines for selling customer location information to third-party firms. The Federal Communications Commission last year fined T-Mobile, AT&T, and Verizon, saying the carriers illegally shared access to customers' location information without consent and did not take reasonable measures to protect that sensitive data against unauthorized disclosure. The fines relate to sharing of real-time location data that was revealed in 2018, but it took years for the FCC to finalize the penalties. The three carriers appealed the rulings in three different courts, and the first major decision was handed down Friday. A three-judge panel at the US Court of Appeals for the District of Columbia Circuit ruled unanimously against T-Mobile and its subsidiary Sprint. "Every cell phone is a tracking device," the ruling begins. "To receive service, a cell phone must periodically connect with the nearest tower in a wireless carrier's network. Each time it does, it sends the carrier a record of the phone's location and, by extension, the location of the customer who owns it. Over time, this information becomes an exhaustive history of a customer's whereabouts and 'provides an intimate window into [that] person's life.'" Until 2019, T-Mobile and Sprint sold customer location information (CLI) to location information aggregators LocationSmart and Zumigo. The carriers did not verify whether buyers obtained customer consent, the ruling said. "Several bad actors abused Sprint and T-Mobile's programs to illicitly access CLI without the customers' knowledge, let alone consent. And even after Sprint and T-Mobile became aware of those abuses, they continued to sell CLI for some time without adopting new safeguards," judges wrote.