[lower]

I don't think there are any border disputes in this area.

Perhaps the hobby-archaeologist wanted to remain anonymous because unearthing historical artifacts with a metal detector is illegal in some places. In Germany one needs a permit at least and must leave finds undisturbed so that archaeologists can see the context of the find. If the hobby-archaeologist is searching illegally, then he/she may be afraid that the location of the find may lead to him/her.