In a move sure to generate controversy, a company that makes RFID tracking tags suggested that its product can be injected into living tissue of immigrants and guest workers to track their movements:
Scott Silverman, Chairman of the Board of VeriChip Corporation, has proposed implanting the company's RFID tracking tags in immigrant and guest workers. ...
Silverman was being interviewed on "Fox & Friends." Responding to the Bush administration's call to know "who is in our country and why they are here," he proposed using VeriChip RFID implants to register workers at the border, and then verify their identities in the workplace. He added, "We have talked to many people in Washington about using it...."
http://www.livescience.com/scienceoffiction/060531_rfid_chips.html - via J-Walk Blog