Mike was hit with an AT&T scam that hijacked his personal information with a phone call thanks to a technique known as "Spoofing." Leo says that often these scam calls are done by legitimate call centers during their "down time." That's why they sound so authentic. Mike said they asked him to participate in a survey about quality of service, told him they would put a $40 credit on his account and asked to verify his zip code and last 4 digits of his social security number. Before giving them that information, though, he asked some basic trivia questions about AT&T. They answered them correctly and without hesitation.
Later he got a call from the real AT&T customer service to verify the activity on his account. He found out that the scammers ordered a phone and SIM card while they were talking to him. So he had everything changed and added additional codes to his credit card number to prevent them from using it. He also should have fraud alert set up, even though lenders may not like it. It may require him to jump through more hoops, but it's worth having the additional protection.
Here's an article about this AT&T scam that Mike dealt with.
Matt from Arkansas called in to say he works for AT&T and says that they will never call you. They handle all their correspondence through text message or email, precisely for security reasons. They will never ask for your social and zip unless you call them.