Fake Coinstar Receipts Busted by Mispelling
A scam to print fake Coinstar receipts was busted in December. Three men had set up a bogus company to buy the special inks used on the receipts. After scamming $5000 from Connecticut area supermarkets, they were only caught when a sharp-eyed store clerk noticed they had spent food as "foood" on one of the receipts.
This suggests a fair amount of inside knowledge about the kind of inks required, and a serious lapse in control over the 'secure' ink.