Comcast has grown its wireless reseller Xfinity Mobile at speed by leveraging its existing cable and internet customer base, but a class-action lawsuit spotted by DSL Reports alleges that the company may have been so keen to sign up new customers, it didn’t fully protect their data or verify new accounts and phone purchases.

According to the class-action suit, unauthorized users (read: scammers) were able to open Xfinity Mobile postpaid accounts for existing Comcast customers online, using easily-available information. A postpaid wireless account fraudulently opened in your name is bad news, as it can affect your credit score, and according to the lawsuit, Comcast didn’t do enough to prevent fraud.

“In an apparent effort to grow its fledgling mobile business segment, Comcast leveraged the personal account information of its existing cable and internet customers to allow the opening of XFINITY Mobile accounts through its online customer portal,” the lawsuit says.”Unauthorized users infiltrated Comcast’s XFINITY Mobile accounts, enabling them to purchase cell phones through the website using already established personal account information from customers’ cable and internet accounts.”

In a statement to DSL Reports, Comcast said that “We are aware of the lawsuit that was filed in the Northern District of Illinois and we are in the process of investigating the claims. Fraud is an issue across the wireless industry, and there is no indication of a breach of our systems. We are prepared to vigorously defend against this action. However, given the pending nature of the litigation, we cannot comment further at this time.”

Chris Mills has loved tinkering with technology ever since he worked out how to defeat the parental controls on his parents' internet. He's blogged his way through Apple events and SpaceX launches ever since, and still keeps a bizarre fondness for the Palm Pre.