Enlarge / The City of Berkeley, as seen in the foreground, looking west towards San Francisco. (credit: Daniel Parks)

SAN FRANCISCO—Two titans of the legal world faced off Tuesday before the 9th Circuit Court of Appeals in a case that pits the cell phone industry against the city of Berkeley, California. If the court ends up reversing a lower court’s earlier decision and ruling in favor of CTIA – The Wireless Association, it would overturn a new Berkeley city law that aims to alert cell phone users about possible radiation risks by forcing retailers to post signs in their stores.

That law went into effect earlier this year after the cell phone trade group sued to halt it. Earlier this year, a federal judge ruled in favor of the defendants in CTIA v. City of Berkeley, allowing a municipal ordinance to stand, with one small revision.

This photo showing the required warning was taken Monday at a cell phone store along Shattuck Avenue in downtown Berkeley. (credit: Rebecca Farivar)

The Cellular Telephone Industries Association (CTIA), meanwhile, has argued that this violates the industry’s First Amendment rights, as it compels speech. “This is confusing,” Ted Olson, a former solicitor general under the George W. Bush administration, argued before the 9th Circuit on behalf of CTIA. “What the [Federal Communications Commission] says, your honors, with respect to its findings of cell phones used in the US is that they are safe. What Berkeley’s message says is: ‘Watch out!’”