Sam Moorhead of the Portable Antiquities Scheme based at the British Museum has been commenting on the number of new coins emerging from East Anglia: "The old theory was that there was relatively little currency circulating in East Anglia in the late-Roman period – we know now that's not true because coins are pouring out of the ground" (Maev Kennedy, "Digging deep: An army of amateur archaeologists is rewriting British history", The Guardian, Friday 28 August 2009).
So coins are "pouring out of the ground" (for which understand being found in large numbers by metal-deectorists), and "buckets and Tupperware boxes that amateur archaeologists and metal detectorists fill with battered, corroded, base-metal coins and other finds".
The same report tells us that there are 180,000 metal-detectorists in Britain and that there are 50,000 new recorded finds every year. So if each metal-detectorist is gaining a full "grot pot" (say) once a month, we must must be talking in terms of hundereds of thousands of unrecorded finds every year. The report coincides with the recording of the 400,000th find. In other words this represents some 3 finds for each metal-detectorist for the life of PAS.
The PAS perhaps needs to speak about the scale of what is not being recorded and the information that is being lost.