Judge Says T Mobile Failed to Notify 40M Breach Victims

A King County Superior Court judge ruled that T-Mobile did not properly notify customers about a data breach affecting 40 million individuals, where sensitive personal information was stolen and sold on the dark web. The lawsuit, filed by the Washington attorney general in January 2025, accused T-Mobile of neglecting cybersecurity risks and inadequately informing customers about the compromised data.

Judge Jason Holloway stated that T-Mobile's use of text message notifications did not meet legal notification requirements. T-Mobile plans to contest the ruling.