what happened who were affected from T mobile data breach

“In your groups, identify an insecure practice and suggest asolution related to it. Research andidentify an appropriate model to use in identifying why the practice is notappropriate for information security reasons.Postulate how the insecure practice was put into place.”My part is about what happened and and who were affected from T mobile data breach
My group will use the distillation model used in our text book. pictures below are definition of distillation model.T-MobileBackground-What happened-meWho it affected – meWhat could T-Mobile do –What T-Mobile Customers could of done-distillation model