A group of lawyers focused on protecting open-source and free software has filed a copyright infringement lawsuit against Verizon Communications, alleging that routers the company uses with its Fios broadband service violate the GNU GPL (General Public License).

The Software Freedom Law Center (SFLC) filed the copyright lawsuit Thursday in US District Court for the Southern District of New York on behalf of developers of BusyBox, a lightweight set of standard Unix utilities commonly used in embedded systems. The SFLC has previously filed copyright lawsuits on behalf of the developers against three other companies, but Verizon is by far the largest target.

The lawsuit against Verizon alleges that the telecom giant uses BusyBox code in wireless routers made by Actiontec Electronics. The routers, distributed to customers of Verizon's Fios broadband and television services, contains BusyBox, the SFLC alleges, but Verizon does not provide the source code of BusyBox to customers, as obligated by the GPL.

BusyBox's developers licensed the software under the GPL "to ensure that all users of the program can access and modify its source code," said Dan Ravicher, legal director of SFLC. Verizon has not responded to SFLC's attempts to resolve the issue, he added.

"We reached out to them three weeks ago," Ravicher said. "They never responded in any fashion."

A Verizon spokesman said the company is aware of the lawsuit. "This matter is being dealt with," said David Fish of Verizon. "We've referred it to the responsible third-party vendor."

The SFLC has also contacted Actiontec, but that company has responded, Ravicher said. "We are in what we believe to be productive discussions with them about their issues," he said. "This is why we purposefully did not name them as a defendant in the lawsuit. To the contrary, Verizon has simply ignored us, which leaves us with no option other than litigation to get them to address our clients' concerns."

Both Actiontec and Verizon have obligations under the GPL as distributors of BusyBox, Ravicher said. "When Actiontec distributes to Verizon, Actiontec has obligations," he said. "When Verizon turns around and redistributes to customers, Verizon has obligations. Even if Actiontec fulfills its obligations when it distributes to Verizon, that does not fulfill Verizon's obligations when it distributes to its customers."

The Verizon action is the fourth GPL enforcement lawsuit filed by SFLC on behalf of BusyBox developers Erik Andersen and Rob Landley. The case against Monsoon Multimedia was settled out of court in October, with Monsoon agreeing to remedy its prior violation, ensure future compliance, and financially compensate the developers, according to the SFLC.

Cases against High-Gain Antennas and Xterasys are still active.

The SFLC assists nonprofit open-source and free software projects. Its chairman is Eben Moglen, longtime general counsel to the Free Software Foundation.