[trotsky]

I have no idea if they are required to do so, but it's worth noting that while the government requires a warrant to open US mail and inspect the contents, your agreement with UPS/FedEx allows them to open anything they see fit to.

[mpyne]

To be clear, it allows UPS/FedEx to open it, not the government. Although UPS/FedEx can then voluntarily give it to the government should they open it...