[satan69]

Might be better to UPS it to yourself.. Safer anyway!

[muawiyah]

"The ban follows safety rules set by the International Civil Aviation Organization and the Universal Postal Union, “both of which currently prohibit lithium batteries in mail shipments that are carried on international commercial air transportation,” the USPS alert said"

This has to do with international commercial air transport governed under various treaties, and the two organizations cited above act as a consequence of treaties already in place.

USPS didn't think this one up on their own!