It is currently illegal to melt down U.S. currency for scrap. No scrap metal recycling center will take them. And it doesn't look like that's going to change any time soon. And it's not like you can just melt down pennies in the microwave oven. Any coin scrapping operation big enough to turn a profit is big enough for the government to notice. But I guess this whole thing is predicated on the idea that the government is going to disintegrate soon anyway.