(More entertainingly headlined in the Mirror as £3 MILLION PAEDO SPY FARCE, but I'm not sure how long that link will last.)
The Police will keep tabs on offenders (especially sex offenders) using `satellite tracking', by which they mean some kind of GPS thingy which transmits its position back to Mission Control periodically.
(The answer to the question, by the way, is, ``pretty well, so long as you're not worried about offenders travelling around on the Underground, inside cars or trains, in very built up areas, or anywhere else that a GPS receiver may not be able to see enough of the sky to get a decent fix.'' So that's alright then.)
What we should do is build a great big building and then build a high wall around it. Inside the building we build lots of rooms with locks on the doors, one for each criminal, and facilities like canteens, classrooms etc.
Then hire lots of staff to keep an eye on the criminals to make sure that they don't escape, or do anything criminal, and also to serve them food and teach them how to not be criminals (or whatever the current fashion in rehabilitation is). Hey presto!
Another great thing about this scheme is that we don't have to rely on tagging the criminals to make sure that we know where they are, because they'd always be inside the big building! (Unless they escaped, but in that case we'd be no worse off than under this tagging scheme.)
Even better, while they're inside this big building, their opportunities for committing crime would be much reduced, and anyway the only victims would be other criminals. Oh, and the staff of the facility, but we could pay them extra to compensate for the risk. And probably it'd be pretty easy to catch the offenders when crimes did occur.
- it might cost quite a bit, what with rising house prices and everything; and
- since it doesn't rely on any flakey high technology, it's not going to look very sexy to the Home Office unless it has a really cool name, and I can't think of one.