Hackers used T-Mobiles Bug to steal accounts

T-mobile failed to notice signs of abuse on its network. The hackers were able to access personal data, including the T-Mobile billing accounts, email addresses, and the phone's standardized unique subscriber numbers.
The bug was patched within a 24 hour time frame upon being discovered by a security researcher.
The hackers were targeting sensitive data and used it to convince the provider to issue new sim cards, after which they could gain access to the desired e-mail account. There is no more detailed information, but in theory the hackers could have also used the phone numbers and email accounts to sweep bitcoins from any connected blockchain, coinbase or any other online wallet accounts.