The text of the coupon not only clearly indicates this, but it has a good chance of being complicit in the sale of stolen goods when buying. And when your coupons arrive, you're technically in possession of stolen property. It's just not worth it and it's just not right. Get your coupons legally by printing your limit, cutting out digital coupons, and buying newspapers from legitimate sources.
There are cases where a barcode can be similar and the computer might not notice the difference, but that doesn't leave you blameless. The deliberate use of a coupon for a product for which it was not intended constitutes coupon fraud and is punishable by federal law. Yes, because it's not illegal to buy coupons from a legitimate coupon cutting service that charges to cut it.