A U.S. man is facing federal criminal charges for allegedly selling modified cable modems and software that enabled free Internet access at super-fast broadband speeds.

Ryan Harris, owner of TCNISO, ran a mail-order Web site and retail store in San Diego that sold software and modded cable modems. The products enabled "users to obtain faster, upgraded internet service without paying the premiums charged by the ISP," according to the indictment, which is dated Aug. 19 but was unsealed just last week.

Harris, who went by the name DerEngel, is charged with conspiracy, aiding and abetting computer fraud and aiding and abetting wire fraud, according to the indictment, filed in U.S. District Court for the District of Massachusetts.

Federal prosecutors allege Harris and TCNISO took in more than US$1 million in revenue between 2003 and this year.

Harris and three unindicted co-conspirators created software that modified a cable modem so that it could adopt the MAC (Media Access Control) address used by the ISP (Internet service provider) to identify a paying Internet subscriber's modem.

Those MAC addresses, however, were stolen from paying users using software Harris and his company created, the indictment alleges.

Harris allegedly also modified a configuration file in modems that would then enable broadband speeds up to 10 times faster without paying the ISP more. The modem hacking products went by the names "Sigma," "Blackcat" and "DreamOS," the indictment said.

A more sophisticated product, "SigmaX," was capable of blocking ISPs from "probing" a modem on its network to see if it had been modified.

In the indictment, prosecutors wrote they found that Harris was allegedly seeking MAC addresses and configuration files used in a major metropolitan area in a posting on TCNISO's forum in March 2007.

From 2006 to 2008, prosecutors also wrote they observed others trying to trade or sell stolen MAC addresses with others on TCNISO's forum.

About a year ago, TCNISO sold through its Web site two Motorola SB5100 BlackcatUSB cable modems, three Motorola SB4200 Sigma cable modems and one copy of Harris' book to an undercover FBI agent in Boston. The indictment alleges that Harris assisted the agent during the purchasing process in a subsequent phone call. The modem enabled free Internet access.

Harris was open about his modding, even writing a book called "Hacking the Cable Modem" that has a cover photo of a modem meshed with an unlocked padlock. He is scheduled for an arraignment in Boston on Dec. 17.