who is the master owner of the creator of the account?
IE - if some jerk sends anthrax and the package is seized... they may stop all shipments from say labels purchased wtih CC ending in 1222
Seeing as you can use cash to buy stamps, I don't see why anyone would bother to use full-fledged shipping labels to mail their anthrax.
I am very excited to see this service, although I would like to see more details about the process. I may go ahead and test it out later on today with a small flat rate label.