The letters "FFF" were spray-painted along Ventura Boulevard, a glittering San Fernando Valley strip better known for its Rolls-Royce dealership and sushi bars than for gangs' graffiti.

The affluent teen-agers who painted the letters form groups that "are more like secret societies of the Middle Ages than gangs. They glory in anarchy and destruction," said detective Paul Bishop.

But these teen-agers would rather steal what they want; they believe crime is cool, said Bishop, a veteran juvenile officer.