Here’s what to do if you think you’re affected by T-Mobile’s big data breach

Let’s say an attacker manages to obtain your name, date of birth and Social Security number — if they luck out and find your address and reused password in other data dumps, that might be enough to give them access to your T-Mobile account. If that happens, you could be vulnerable to what’s called a SIM-swap attack, in which the hacker manages to switch control of your phone number to a phone they control. That’s definitely bad, but what could make it worse is if the verification codes sent by services like Amazon, Twitter and many banks are delivered via text message. In that case, the keys to your online kingdom could be ferried straight to someone else.