I guess -- the best policy, is outa sight and outa mind
They're a brazen lot, as Aussies are of convict heritage -- they don't get it, until you thieve from the theives.
Now, with all the old mobile phones around these days --couldn't one be conceled in the trailer(or equipment) and when it is plugged in (electrically activated ) the phone becomes live, and rings you --the signal could then be traced . Should be possible
--lets hear it from the geeks