Washington State Attorney General Bob Ferguson says T-Mobile has been refusing to provide the documentation needed for a security probe.

T-Mobile suffered a massive data breach in 2021, one that impacted some 76 million Americans and led to a $350 million settlement. Law enforcement has been investigating the incident, but the Washington AG says the carrier has not been cooperating, according to GeekWire.

“Throughout this investigation, T-Mobile has either provided insufficient responses, or refused to respond outright, to the State’s Civil Investigative Demands (CIDs), all while continuing to suffer repeated data breaches,” alleges the AG’s office in the filing.

As the filing mentions, T-Mobile has continued to suffer breaches since the 2021 incident, including one disclosed in January 2023 and another in May 2023. To make matters worse, hackers claim to have accessed T-Mobile’s systems more than 100 times in 2022 alone.

Of the top three carriers in the US, T-Mobile easily has the worst security track record over the last couple of years. Withholding documents from law enforcement officials investigating one of these incidents is certainly not a good look for the magenta carrier.