It’s been a bad week for wireless companies and their subscribers, with data for 70 million AT&T customers reportedly for sale online.

Just days ago T-Mobile acknowledged a data breach impacting tens of millions of users, the complete scope of which may still not be fully clear. According to Restore Privacy, a hacker is claiming to have the data of 70 million AT&T subscribers and is looking to sell it online.

In a statement to Restore Privacy, AT&T is denying the data came from its systems.

Based on our investigation today, the information that appeared in an internet chat room does not appear to have come from our systems.

The hacker maintains the data is, in fact, from AT&T. The hacker, known as ShinyHunters, is also a well known entity in the hacking community, with a long list of successful hacks against other companies, lending credence to the claims.

In the meantime, Restore Privacy got a look at a sample of the data and, while they could not confirm it came from AT&T’s systems, the data included a distributing amount of sensitive information. The data included names, social security numbers, phone numbers, addresses, email addresses and dates of birth.