Time Warner Cable said on Wednesday that as many as 320,000 customers may have had their emails and passwords leaked.
In a statement provided to NBC News, the cable giant said "there are no indications that TWC's systems were breached," and suggested the mails may have been acquired earlier by other means, such as malware, phishing attacks on subscribers or security breaches at companies that stored TWC customer information.
The company is now working with the FBI, which first informed them of the stolen emails and passwords, all (at least all that were reported to TWC) belonging to the Roadrunner service.
Customers with emails ending in "@rr.com" may be affected and should be receiving communications from TWC shortly with indications on how to reset passwords.
The TWC spokesperson indicated that data provided by the FBI was part of a wider disclosure including other ISPs. NBC News will update this story if more providers or services are found to have been affected.