As the parents of scouts we suspect you are more responsible, thoughtful and socially aware than average. Consequently we should like you to do a little research regarding the scout group metal detecting rally at Laverstoke Park, Hampshire that your youngsters may have recently attended.
You have a choice in the event of further invitations. Either you can believe a metal detecting club and a global detecting manufacturer (who financed the event and handed out prizes and goody bags) that artefact hunting is a fine thing to get young people interested in or you can heed what The Council for British Archaeology says :
“As long as it remains safe then it is better to leave the evidence for future generations to investigate with better techniques and with better-informed questions to ask. Usually, intervention is only justified if the evidence is at risk of being lost or damaged, through development, climate change, or agricultural practices. In this case, any excavation work has to be carried out carefully to ensure that we extract as many clues as possible not just about any objects that are found, but about the full circumstances of the way in which they were initially buried and any materials or evidence buried in association with them”.
Update: Here’s an account of scouts using metal detectors as part of a proper archaeological exercise designed to harvest knowledge for society not personal gain, which “helped them achieve their heritage badge”. (All parents should note the difference.)