It’s a combination of some good standardized IT security tools, some spycraft, and a heavy dose of paranoia. Tor allows you to (in theory, provided not enough of the network has been compromised) make a web connection to a remote Tor site such that you are completely anonymous and the site is authenticated as definitely owning the domain name you used, while not having any good clues about WHERE or WHO that site is. Atlantis makes it easy for people engaged in transactions to use GPG to exchange public encryption keys so that they can send messages such that only the receiver with his password to unlock his private key can read them. BitCoin and LiteCoin allow you to transfer currency pseudo-anonymously using a consensus-based peer-to-peer network, such that the sender and receiver need not know each others’ identities, and the transaction cannot possibly be undone unless both parties agree to it (send the money back). (Edit: Atlantis provides ESCROW of the transferred funds in an Atlantis BitCoiin or LiteCoin wallet, until the rest of the transaction is settled, Ebay-style. My point was, there are no credit-card style “charge-backs”.)
I am not a user, so I am speculating here: The physical contact part of the transaction – mailing a package from point A to point B – seems to be depdending on simply not being noticed among the torrent of regular mail.
