This is a two-part question:
What do you do if while you are at home during Shabbos, someone knocks at your door, and when you open it a delivery person (UPS/FedEx/USPS/DHL etc.) hands you a package that you ordered? Is the package muktzah? Should you take it? If the deliverer says "Should I sign for this for you?" what do you say?
What if you do not answer the door and the deliverer leaves the package at your door (not in anyone's way, though)? Are you allowed to bring the package inside to protect it from possible theft? Does the crime rate in your neighborhood affect this decision?