Just as there are with most things in life, there are rules to couponing. And breaking the rules could be against the law.
Here is a list of "Don'ts" from the Yahoo Finance website.
Don't make your own coupons. Counterfeiting coupons is a crime just as counterfeiting money is. The F.B.I. charged a man for doing that last year.
Don't photocopy coupons. It's the same as stealing because the stores accepting the fake couponing won't get reimbursed for their value.
Don't remove expiration dates for the same reason - stores won't get their money.
Don't buy coupons. While buying them isn't illegal, they could be fake.
Don't steal newspapers. If it's not yours and you take it, that's theft.
Don't take things out of trash receptacles or bins. You might call it scavenging, but the law calls it theft. You can get in trouble for even going into the bins - that's trespassing.
Don't make multiple passes to bypass the store's or cash register's coupon limit.
Don't take multiple coupons. Some products have stick-on coupons you can pull of a product to use when you buy it. Don't' take them off every item on the shelves. The same goes for hitting the back button to force a limited Coupon.com coupon to print twice.