This is a question that’s moved a fair way in the past few days, from around 50% to 79%. It’s a field in which I have no experience or expertise, but I thought I’d reprint a couple of comments from @the_predictor (the run-away leader on our narrative leader board) and @jna. They did some digging around on the subject and had this to say:
@the_predictor Wednesday 18th May
“The British government has just announced in its legislative programme for the next year a plan to allow many prisoners out of prison wearing a “new generation” of satellite tags. Satellite tags are already used on birds that weigh only 5 grams (photo here) and are far smaller than the ankle tags used in the criminal justice system (photo here), although they do have aerials sticking out of them.
It could be that tags for humans will at first have an implanted rice-grain size chip (that stays put and is read by close-proximity scanners when services are accessed and at routine checks) combined with a strapped-on device communicating using the mobile phone network (locating using triangulated GPS signals received).”
@jna Monday 16th May
“There has been a drip-drip on this possibility for years, but once we screen out the nonsense, we don’t have to rely on statements by Kevin Warwick and “post-humanists”. There are statements of intent by very powerful companies such as Oracle (Jeremy Nettle) and Google. For Google’s statements, see here and here. It is very likely that the replacement for Google Glass will involve a technology that skips over the “wearing” bit. My guess would be that mass chip implantation will be piloted in one a hi-tech-heavy but out of the way country.”
All I’d add is that for a “hi-tech-heavy but out of the way country”, I will be looking to Estonia who are global leaders in advanced, digital national ID systems.