On flattening pennies and other coins, the US Mint site has this to say:
Section 331 of Title 18 of the United States code provides criminal penalties for anyone who “fraudulently alters, defaces, mutilates impairs, diminishes, falsifies, scales, or lightens any of the coins coined at the Mints of the United States.” This statute means that you may be violating the law if you change the appearance of the coin and fraudulently represent it to be other than the altered coin that it is. As a matter of policy, the U.S. Mint does not promote coloring, plating or altering U.S. coinage: however, there are no sanctions against such activity absent fraudulent intent.
Note the key words “fraudulentl intent.” In other words, it’s okay to flatten a coin, but don’t expect to be able to use it to pay for any purchases.
Section 333 covers paper money; the Bureau of Engraving and Printing goes on to say:
Under this provision, currency defacement is generally defined as follows: Whoever mutilates, cuts, disfigures, perforates, unites or cements together, or does any other thing to any bank bill, draft, note, or other evidence of debt issued by any national banking association, Federal Reserve Bank, or Federal Reserve System, with intent to render such item(s) unfit to be reissued, shall be fined not more than $100 or imprisoned not more than six months, or both.
So, basically, you can write on bills all day long; just don’t go changing the face value or the Secret Service will getcha.
Incidentally, it is illegal to flatten Canadian coins in Canada. Penny smashers in Canada have to use blank copper/zinc disks. This is because their law is incredibly short:
- Every one who
(a) defaces a current coin, or
(b) utters a current coin that has been defaced,
is guilty of an offence punishable on summary conviction.
R.S., c. C-34, s. 414.
And JS Princeton–back off on the “stupid” penny machines! We Elongated Collectors (http://www.money.org/clubs/tec.html) are a mighty bunch–fear our penny flattening power!