A security breach in 2022 compromised AT&T's data, affecting almost all cellular customers, mobile virtual network operators using AT&T's network, and landline customers linked to cellular numbers. The breach exposed AT&T records of calls and texts from May 1 to Oct. 31, 2022, totaling over 100 million U.S. customers and 2.5 million business accounts. AT&T is investigating with cybersecurity experts, stating no personal information was leaked.