I suppose the only other comment one could make is that the use of such equipment must be illegal in the UK because it involves the reception of radio signals for which Joe Public cannot obtain authorisation. However, one imagines that this technicality will not prevent the sale and use of thousands of them!!
In these days of paranoia, when a friend of mine was handed a ticket by the Police suggesting he might be a terrorist when he was simply looking at aircraft on an airfield from a public road, one wonders what the official line might be if the Police found one using such a device near an airport?