Well, at least it doesn't compromise the cheaper resellers (like Boost or Mint Mobile or Metro). Ironic that the cheap resellers are safer than the supposedly premium network.
Yep, here you go: "No Metro by T-Mobile, former Sprint prepaid, or Boost customers had their names or PINs exposed," T-Mobile said. "We have also confirmed that there was some additional information from inactive prepaid accounts accessed through prepaid billing files. No customer financial information, credit card information, debit or other payment information or SSN was in this inactive file."