A French company, Lyberta, has just dropped plans to fit children in several nurseries in Paris with electronic tags, after a newspaper revealed the scheme. Trade unions, councils and civil liberties groups were indignant at the invasion of privacy. But the response to the idea in online forums was much more divided: "I have been longing for this ever since my first child was born," a woman wrote. "My three-year-old daughter walked out of her infant school and the teachers found her in the next street … I would rather put a tag on my child than sign up for a kidnap warning scheme."

In a world that seeks to eliminate risk altogether, are parents prepared to tag their children? "The basic problem is that we are being swamped by technology, but society has largely failed to address the topic," says Alex Türk, the head of France's Commission for Information Technology and Freedom (CNIL). Discussion on the subject has barely started, whereas the technology is there, and working. What might have seemed science fiction a decade ago is now possible, thanks to radio-frequency identification. RFID tags, with a chip and an antenna, are used to store data for remote access. Once fitted with such a device, a wristband or garment becomes smart, unique and locatable.

Some RFID chips are passive, like the swipe cards for transport systems that use transmitter-readers. Others are active, where the chip has its own power supply and transmits a signal at regular intervals. A web of receivers monitors the area under surveillance, locating chips and their bearers. Nearly 150 maternity units worldwide already use this system. Wherever they are taken in the hospital, a track can be kept on babies wearing wristbands with active chips. An alarm is tripped if the band is cut, covered or removed from the unit. "We won our first contract with the maternity hospital in Birmingham, in the UK," says the CEO of France's Bluelinea, Laurent Levasseur. "A newborn baby had been kidnapped shortly before." The company now supplies customers in 17 countries, including the US, Hong Kong, Kuwait and Spain.

"Portugal and Brazil have even passed laws to make individual security devices compulsory in maternity hospitals, to combat kidnapping and swaps," Levasseur says. In 2009, some 300,000 infants were tagged around the world.

In France, 50,000 babies were tagged in 2009. "About 30 hospitals use our wristbands, but the subject is still something of a taboo," Levasseur says. "Last year there were two attempted kidnappings in French maternity units, with one in our area," says Philippe Cruette, deputy head of the Bordeaux-Nord clinic. "We were keen to respond to the concerns of mothers who had heard about these in the media." RFID wristbands have been available since January. Cruette adds: "Roughly half the mothers ask for a tag, mainly young women having their first baby."

Bluelinea, however, has decided not to equip nurseries or schools. "The first inquiries we received were from Belgium ... I turned them down," says Levasseur. "There is an unfortunate side effect with fitting tags to minors: they lose all sense of responsibility. We can't just do anything simply because it's technically possible."

Such considerations have not registered in the US. This September, an infant school in Richmond, California, kitted out its three- to six-year-olds with basketball jerseys with active RFID tags, to save 3,000 supervisory hours.

"It is a federally funded school and pupils come from very underprivileged backgrounds. The parents do not really understand what is at stake," says Nicole Ozer, the policy director at the American Civil Liberties Union of Northern California. "The system cost $160,000, money that could have been spent hiring more teachers. What's more, it has been proven that these systems can be hacked, exposing the kids to even greater risks."

This is not the first experiment in California. In January 2005 a primary school near Sacramento invested in tags for its pupils, but had to shelve the scheme after six weeks in response to parents' concern about a form of surveillance that was not justified by any real threat. But the initiative did last long enough for civil liberties groups to draft a bill that would impose stricter controls on the use of ID tags in schools.

"The bill gained massive support and was passed in 2007," Ozer explains. "It required parents to be informed about the technology and to give their assent. But the governor, Arnold Schwarzenegger, never signed the legislation into law, claiming at the time that it was pointless, as no further cases had been reported in California." Recent developments have proved him wrong.

"I'm not very hopeful. Society is going to be shaken up over the next 15 years because private life as we know it will cease to exist," says Türk. "We sometimes need to say 'no' to the temptations of technology. We are going to see even smaller devices, and the tinier they become the more difficult it will be to legislate. The French parliament should address RFID tags and promote genuine debate at home and abroad."

He is convinced the tags and their positioning systems should require authorisation by the CNIL before they can be used, as has been the case with biometric systems in France since 2004. That way the watchdog would have been alerted before plans to equip Paris nurseries were approved.

This article originally appeared in Le Monde