As of next week, the United States Postal Service, or USPS, is banning all international shipments containing lithium ion batteries,....
The USPS says it may change the ban on January 1, 2013 and allow customers to mail certain quantities of lithium ion batteries internationally, including to APO and FPO locations, "when the batteries are properly installed in the personal electronic devices they are intended to operate."
The design of lithium batteries does create an inherent danger of fire. It's rare, but very possible. When you think about the numbers of devices being shipped now days, that increases the chances of an accident quite a bit. The manufacturers and sellers will just have to find a method to work around the issue. For a small seller, you;d maybe just ship without a battery. Not sure why they are only banning for int. stuff though.
But I love how the comments under the story instantly degenerated into a "shut down the postal service" rant fest. lol People are so stupid.