A big problem to me is that typically, you will be asked to sign for package with a PO box (not just for certified mail, but packages too large for your box or held mail), and this can be very troublesome if the Feds are on to you. If you use false identification with your PO box, you will have committed another federal crime to add to your troubles. Using your home address with an alias, eliminates some of the problems associated with using a PO box.