I don't know of any stores that accept an internet-printable for a free item, but they take all of the rest, up to $5 usually.
A woman here was arrested when she brought in (from what I understand it was quite a few!) copied coupons. That is fraud, and all of the numbers on the coupon were identical. When you print them, they have unique numbers attached to the coupon (not the barcode).
There has been a crackdown, but I'm shocked that Target won't accept internet printables at all...they have them on their website!