RFID Guardian

OK, here's the neatest hack I've seen in a while:

Melanie Rieback, a graduate student [now assistant professor -- gefeliciteerd!] at the Vrije Universiteit Amsterdam, has built the RFID Guardian a firewall for RFID tags. You tell it who you want to be able to read which of your tags, and it jams any requests you don't want.

To do this, it uses about 12K lines of carefully-crafted code, an RTOS and "a beast" of a processor in order to meet the hard real-time deadlines required to fake out an RFID reader.

Maybe this was the "something missing" from the previous post on California's RFID law?