RFID chips, first conceived of as inventory management devices, made the leap to living beings in the cattle industry.

“An ISO compliant RFID tag to provide each head of cattle a unique code, plus a rugged field reader that can automatically upload data into the BeefLink software on your PC.”

http://www.y-tex.com/electronic.html

Advocates of benefits to humans, such as the proposed medical use here, have been overwhelmed by ham-handed Homeland Security passport proposals. My guess is there won’t be mandates, and many people will voluntarily choose implants.

Joseph Feldman, MD, Chairman of the Department of Emergency Medicine, Hackensack University Medical Center, said “We look forward to using the VeriChip System to assist in patient identification and access to medical information. Particularly beneficial to patients with chronic illnesses…”

http://www.hoise.com/vmw/05/articles/vmw/LV-VM-09-05-24.html

And WalMart’s inventory control needs are going to continue to drive the state of the art, which may be where technical fixes to privacy concerns actually come from.