I know it's illegal to copy paper bills (they have a term for it it: counterfeit! No joke, with today's technology, it can be done and the treasury department takes it very seriously.), however, I don't know if coins are the same as they are a different material. To be sure, you can check with the Treasury department. Easiest to do is Google search!
~well, you peaked my curiosity, so I did the search! LOL I found a "how-to scan coins" on eBay
http://reviews.ebay.co.uk/How-to-Sca...00000001681729
I actually didn't have a whole lot of luck finding a definitive answer. I think it may be acceptable, IF, you write "copy" on them. You can make the word "copy" like a watermark, translucent, so unless you look for it, you don't notice it imediately. Wish I could have found a more complete answer. If you find out more, please post back here for future reference!