In the US, shipping companies often have relatively limited ways for you to get your package and if you don't jump through the proper hoops they don't give you your package. While I understand why they do this from a security perspective, I'm curious what laws you would actually be breaking if you simply picked up your package and walked out the door or took it off the truck.
Assuming you have already paid for the package and don't intend to scam the shipper or the vendor in any way, what, if any, laws would you be violating by removing the package against the shipping company's will?