@CH: encouraging self-control among the spotters community is a very good idea.
OTOH you confuse me with the "no registrations whatsoever" phrase - my microlight at least carries a registration, and so do all I have yet seen. Only the US'an single-seaters have none,
AFAIK.
Theft of Rotaxen is not an increasing issue, in my observation, one hears of a handful per annum since several years. The pdf I linked to seems to confirm this.