Hacking FasTrak

I've never used the FasTrak debit system for the tollways in California when I lived there, but The Register recently reports that an exploit has been found. I can't believe that FasTrak apparently transmits its unique ID number in the clear.

Not that I use it here, but I wonder what sort of vulnerabilities and countermeasures exist for the Electronic Toll Collection (ETC) system in Japan. Or おサイフケータイ services for the mobile devices used in Japan.