Advertising Damaging Metal Detecting: Physics, Ethics and Joined up Thinking

Heritage action mirrored my concern about the tone of an advert for a certain brand of metal detectors carried by UK magazine "the Searcher". We think there should be wider awareness of the need for better conservation of the incomparable but often-threatened prehistoric sites of Britain, Ireland and beyond. Showing someone metal detecting right in the middle of a stone circle is awful: "even in Bonkers Britain where you can mine for artefacts to your heart’s content on 950,000 unprotected archaeological sites, you can’t do it at stone circles – so what the blazes were the editors of The Searcher thinking of? Who knows?"  Of course it never occurred to the editorial team of said magazine to actually come onto either blog and explain - still less apologise for their lapse (tekkie mantra number nine: 'Heads-down-tight-lips-it-will-blow-over'). Heritage Action end their text:

We await with interest to hear what excuses some of their colleagues concoct to minimise it, as they minimise everything bad that happens in their activity. Our betting is “whoops, administrative error, why make a fuss?” or perhaps they’ll take the standard “not us guv” line that’s taken about so many instances of bad behaviour “Don’t judge us by that. Only a very tiny proportion of detectorists are as stupid and uncaring about heritage protection as The Searcher’s editors”!

That evening, there was a prime example, "Peter" (so who would that be then? President of some metal detecting club maybe?) writes [31/05/2014 at 21:40]:

You really need to study the physics of metal detectors and there (sic) limitations.

There there, where where? In stone circles? Is this guy perhaps claiming that there, in stone circles, metal detectors will not work (for example because of the earth forces which the megaliths focus, which perhaps bring metal detectorists' hands out in scabies if they try)? Is that the sense behind this comment? Or is this semi-literate trying to suggest that metal detectors are physically unable to penetrate far into turf undisturbed for millennia, so anything found was anyway lying right on the surface? Why, though, do Heritage Action "really need" to study the physics of the detection of variation in an electromagnetic field in order to say that this sort ofadvertising is giving entirely the wrong message about so-called "responsible collecting"?

In any case, if the latter really exists, after having fifteen million quid thrown at it by a hopeful establishment, why does "Peter" not agree, "yes this picture is awful, I'm cancelling my subscription to the magazine which carries such irresponsible material, damaging the reputation of metal detectorists everywhere"? This has nothing to do with "Physics" Peter, but an ethical stance to an exploitive approach to an activity.