[htprobgx] Curbing bike theft with GPS transponders

We leave two things out in the open: cars and bicycles.  Car theft has been curbed a lot with technology, for example electronic ignition and car alarms.

Hide GPS transponders within certain bicycles in high-theft areas.  The transponder calls home with its location via a data plan on the cell phone network.  Is bike theft organized such that discovering, destroying, and punishing a few "rings" sufficient to radically reduce theft?

A bit of a technological challenge to conceal whether a bicycle has a transponder, so thieves don't know which to avoid.  Inductive charger to avoid external leads, but the charging only starts after cryptographic authentication (or else an inductive charger can be used as a scanner).  Or somehow charge it from bicycle power itself, though this may be even more difficult to avoid externally visible markers.

Law enforcement ought to do this, but can vigilantes do it without them, at least until an arrest or raid is necessary?  Ask for donations for such a project.