T-Mobile confirmed that unauthorized access to its IT systems had occurred, however, the company said it has not yet determined how much, if any, customer data had been stolen.
"We are confident that the entry point used to gain access has been closed, and we are continuing our deep technical review of the situation across our systems to identify the nature of any data that was illegally accessed. This investigation will take some time but we are working with the highest degree of urgency. Until we have completed this assessment we cannot confirm the reported number of records affected or the validity of statements made by others."
https://investor.t-mobile.com/news-and-events/t-mobile-us-press-releases/press-release-details/2021/TMobile-Cybersecurity-Incident-Update/default.aspx
