"Los Angeles city officials said the signs, made mostly of vinyl, had proliferated since December, when the City Council passed a temporary ban on billboards and large signs. The stopgap move was an effort to give the city more time to close loopholes in a 2002 law intended to curtail billboard advertisements."
"Jack Weiss, a city councilman who wrote the temporary ordinance, said the original legislation was supposed to put a stop to the supergraphic signs. 'Instead,' Mr. Weiss said, 'the supergraphic companies have plastered their signs up all over the city and are thumbing their noses at the law.'"
"The Fire Department estimates that more than 100 buildings from downtown to the coast have illegal signs."
"The city has been blocked from enforcing the 2002 law because of legal entanglements, including lawsuits by billboard companies over free-speech rights. In 2006 and 2007, the city settled lawsuits with three of the largest billboard companies - CBS Outdoor, Clear Channel Outdoor and Regency - allowing them to convert as many as 850 print billboards to electronic ones."