http://i.ebayimg.com/images/g/fjMAAOSwP~tW4ZR5/s-l1600.jpg
Says one per household.
Anyways, not sayin it isn't dumb, because they obvi can't stop the codes being used, but you prob won't be able to do much to fight it
I was assuming he uses coupons found online, since they told him he uses too many. I buy a lot at lowes and I'm signed up on their list, but they only send me maybe a couple coupons each year.