Does Google Earth Need Substantiation Guidelines?

The British press is reporting that someone has spotted a word that we won't use here on a rooftop courtesy of Google Earth.  That raises the question, will advertisers start using rooftops as the next advertising medium?  Sound far-fetched?  Remember Mail Pouch tobacco?  At its heyday in the 1960s more than 20,000 barns were painted with its slogan across 22 states.  Still, its unlikely that Google Earth will have to issue substantiation guidelines anytime soon.  Although the FTC has encouraged media to look closely at the advertisements they carry and from time to time has made threatening noises about bringing cases against media that disseminate flagrantly false claims, the agency has yet to take on the daunting first amendment issues likely posed by bringing a Section 5 case against a broadcaster.