The ban begins on Wednesday, when legislation signed on May 30 by Gov. James Doyle goes into effect. The act dictates that no person may force another to have a microchip implanted in his body. Violators face fines of US$10,000 each day until the chip is removed.

A spokeswoman for Doyle said the law targets RFID technology, though it bans the implantation of any microchip without consent.

"I'm hoping other states will follow," said state Rep. Marlin Schneider, a Democrat who sponsored the bill. While Schneider acknowledged that he knows of no case where an RFID chip was forcibly implanted into a person, he said he believes that proactive legislation is necessary as the technology quickly advances.

Schneider said he is also concerned about current commercial uses of RFID technology. "There are a number of issues here, potentially," he said.

Proposed laws that seek to limit the use of RFID devices because of data privacy and security concerns are under discussion in a total of 19 states, according to Douglas Farry, managing director of the government affairs practice at McKenna Long & Aldridge LLP, a Washington-based law firm.