Quote from Cliff in The Days of Wine and Neuroses
Cliff: Boy, these Mylar balloons are a public hazard. Paul: What do you mean? [grimaces as he realizes he invited Cliff to talk] Cliff: Well, Mylar is a form of metal, Paul, and if you release these things they get caught up in the high-tension wires; they cause an arc, sending a shower of sparks all over the place, and it hey, it could put out the lights of a whole city block. Norm: All right. [Norm, Cliff and Paul head for the door with their balloons]