Even the watered-down version couldn't pass muster. San Francisco's ordinance requiring retail outlets to inform consumers about the (alleged) effects of cellphone radiation has been blocked by a federal judge.

Upon passage, San Francisco's ordinance was challenged by industry trade group CTIA-The Wireless Association, which claimed the ordinance's requirement that retailers post messages about cell phone safety violated the First Amendment. San Francisco initially agreed to amend the ordinance after the CTIA filed suit, and made some changes, but they weren't enough. Judge William Alsup found that the ordinance failed the sniff test on both scientific and First Amendment grounds.

"Whether or not cell phones cause cancer is a debatable question and, at this point in history, is a matter of opinion, not fact. San Francisco has its opinion. The industry has the opposite opinion," wrote Judge Alsup.

The fact-sheet required by the ordinance is "misleading and must be corrected," notes the judge. "Although each factoid in isolation may have an anchor in some article somewhere, the overall message of the fact-sheet (and the poster, for that matter) is misleading by omission in two important ways. The overall impression left is that cell phones are dangerous and that they have somehow escaped the regulatory process."

The World Health Organization issued a report that seemingly butressed San Francisco's position in May when it labeled cellphones "possibly carcinogenic," meaning that there is "limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals." But results of a massive, 15-year-long study released earlier this month showed absolutely no link between cellphone use and cancer, echoing the findings of numerous other studies.

The judge left the door open to the possibility that a revised "fact sheet" could pass muster and stayed the enforcement of the law until November 30 so that both sides can file appeals. San Francisco has already promised to do exactly that.