[dogscoff]

It's already being done: Tracker implant {link}

It's all hype and (fortunately) unfeasible. If you think about it, you'd have to have an object implanted in the girl's arm with the same kind of tranmission capabilities as a mobile phone. Implanted under the skin. People are worried about the health risks of regular phones, what do you think this would be like? What if the battery leaks? How would you recharge it anyway?

Take a look at this:

http://www.ntk.net/index.cgi?b=02002-09-06&l=57#l

and this:

http://www.kevinwarwick.org.uk/

IMHO this child-tagging lark was the stunt that tipped Kevin Warwick from harmless publicity-muppet to Orwellian bull****ter bastard.