Here is yet another example of how a hoard reported by amateurs has given a lead to archaeologists that has resulted in a reassessment of local history. See
http://www.dailymail.co.uk/news/article-2022699/Treasure-trove-ancient-coins-prove-Romans-controlled-UK-thought.html?ito=feeds-newsxml
Archaeological cranks complain that the UK does not give them exclusive rights over the past, but what are the odds archaeologists would have ever found the remains of Roman settlement had they not been alerted by metal detectorists?
The pragmatic genius of the UK's Treasure Act and Portable Antiquities Scheme is that it directs public interest in finding ancient coins and other artifacts in a way that benefits everyone.
The proof can be found on the PAS website. See
http://finds.org.uk/
Can the countries archaeological hard liners look to as models like Italy, Greece and Cyprus report similar results? Of course not.