Muhammad Fahd, 34, of Pakistan recruited AT&T employees to remove company’s protection against unlocking phones. Fahd would provide international mobile equipment identity (IMEI) numbers for cell phones that were locked to the carrier. He and his partner Ghulam Jiwani (deceased) paid over one million dollars and were able to unlock this way more than two million phones. He was arrested in Hong Kong on February 4, 2018, and extradited to the U.S. on August 2, 2019.
Source: https://www.bleepingcomputer.com/news/security/fraudster-unlocks-over-2-million-atandt-phones-pays-1-million/