I've done this, because I thought it was good to reuse a box! Like someone sends me a priority box....so I save it, then when I ship something to someone and that specific box holds it so perfectly, then I use that box...I didn't take it from the PO, and someone already paid for it being priority box prior to my using it....is that really that wrong? I guess there is no recycling when it comes to Priority boxes huh? sorry but that just kinda seems dumb!