Suzanne, grandmotherly with neat snowy hair, prim gray anorak and white shirt fastened at the collar with a blue brooch, glanced furtively up and down the subway platform bustling with out-on-the-towners. Slowly, the station emptied; the coast was clear. Spinning on her heels, a mischievous glint in her soft blue eyes, she whipped a red wax crayon from her handbag and, wielding it sword-like, scrawled her fury across a billboard advertising home appliances. "TOO MANY THINGS, NOT ENOUGH POETRY!" she wrote. Pow! Thus another blow was struck in a fight raging in France against advertising. The attackers are a small,...