The Electronic Frontier Foundation (EFF) urged a federal court to return two domain names seized as part of the U.S. government's "Operation in Our Sites," an ongoing campaign against websites that illegally provide access to copyrighted material.

"This misguided intellectual property enforcement effort is causing serious collateral damage to free speech rights," said EFF Intellectual Property Director Corynne McSherry. "These domain seizures should cease unless and until the government can fix the First Amendment flaws inherent in the program."

The U.S. Immigration and Customs Enforcement's (ICE) Homeland Security Investigations (HSI) announced in February that the domain names of ten "linking" websites had been seized for allegedly providing access to illegal, pirated telecasts of the National Football League, the National Basketball Association, the National Hockey League, World Wrestling Entertainment, and the Ultimate Fighting Championship.

Visitors to these websites now only see a banner that says the domain name was seized by the New York office of ICE HSI because of criminal copyright violations.

The websites did not themselves host any illegal content, but allowed users to easily browse for links to third party websites that were hosting pirated videos, according to ICE.

EFF's amicus brief (PDF) was filed in support of a petition from Puerto 80, the Spanish company that owns the streaming sites Rojadirecta.com and Rojadirecta.org, which were both seized by ICE.

A Spanish court found the sites did not violate copyright law.