Erick Schonfeld argues that despite the concerns of privacy advocates, the technology of implanting medical chips into the human body "is already more helpful -- and more common -- than you might imagine."

A Florida company Thursday said that it will begin marketing and selling a microchip that can be implanted under the skin, after receiving the go-ahead from the U.S. Food and Drug Administration.

Radio-frequency identification chips, which have found a home in applications ranging from toll road passes to smart retail shelves, may be close to taking up residence in the human body. A Florida-based company has introduced a passive RFID chip that is compatible with human tissue, and the developer is proposing the chip for use on implantable pacemakers, defibrillators and artificial joints.

A microchip manufacturer is proposing that foreigners who pass through customs or immigration could be injected with a computer chip, allowing officials to monitor their activities better and keep terrorists out.