Terror Art

Yesterday, 37 black boxes were fastened to walls and girders throughout Union Square subway station in Lower Manhattan. Each box featured a single white word written in contrast with the black: fear. Within minutes after they were discovered (presumably, they were put there in the early morning hours), the subway was evacuated, trains were diverted, and police and bomb squads were called in. False alarm, of course. But why wasn't the word art mentioned in the story?