T-Mobile said it is investigating a claim on an online forum post which says the personal data of over 100 million users have been breached.

“We are aware of claims made in an underground forum and have been investigating their validity. We do not have any additional information to share at this time,” a T-Mobile spokesperson said.

The forum’s post does not mention T-Mobile, but the hacker has obtained data of over 100 million people and that the data came from T-Mobile servers, according to the report in Vice’s Motherboard.

The data included information such as social security numbers, phone numbers, names, physical addresses and driver licenses information.

The hacker is asking for 6 bitcoin for a subset of the data containing 30 million social security numbers and driver licenses, while the rest of the data is being sold privately.