http://online.wsj.com/article/SB10001424127887324904004578537692730996164.html

http://www.cato.org/sites/cato.org/files/serials/files/regulation/2008/2/v31n1-6.pdf
besides, it just means cheaper coins for us long run. if they sell too much, and lose money when they can't cover, that's a deterrant. It's illegal if they don't cover.