Thou shalt not steal from your hotel—no matter how big or small the item might be. Take New York's iconic palace of luxury, the Waldorf-Astoria. Over the years, larcenous lodgers have walked off with ornate art deco grillwork from the heating and air conditioning units. They've filched guestroom doorbells. They've absconded with brass-plated mail slots from the corridors. "Some guests will take pretty much anything," says Matt Zolbe, the hotel's director of marketing, "even if it's bolted down." The famed hostelry has embarked on an Amnesty Program to retrieve some of that long-lost plunder, specifically historic, pre-1960s swag. The question is, will the program be enough to compel high-rent kleptos to return their purloined property?