Christos Tsirogiannis (Photo by DW, J. Di Marino)

It's estimated that there are now more than 10,000 metal detector users in England and Wales alone. They've been making an impact. In 2011, close to a million artifacts were found by hobbyists. Nearly 1,000 of those could be classed as treasure - precious metals discovered by metal detector users. 

No harm done? 

But not everyone is pleased. Archaeologist and illicit antiquities researcher at Cambridge University, Christos Tsirogiannis, is one of those concerned. He says the amateur archeologists are damaging important sites. 

"Every object has an amazing historical value, especially when it's found in its actual and original archeological context," Christos Tsirogiannis explains. "If something is extracted violently and by an uneducated, non-specialist person from its original context, this cannot be reconstructed."

"I'm sure that there are several people who are operating metal detectors and they do it just for excitement," he says. "But even in a legal way, the destruction that they generate is really big, and it is an unfortunate phenomenon that it is still legal."