I read all the replies on this thread so far, including the link that everex5 gives. Basically it seems that someone's gone into the minutia of fed. level laws there, and determined that any resource in the ground, belongs to the govt. But ..... isn't anyone hear realizing that the same can be said of Mexico? And the same can be said of England? Yet as we all know, detecting goes on in these places. Detectors are a common site on Mexican tourist beaches. But sure enough, if you ask enough questions, of enough border lawyer consulates there, sure, you might come up with something about how Mexico owns the resources under the ground (hence, for example, if you ever discovered oil on your own land, it belongs to the govt, not you. Or in England, same thing: items under the soil belong to the "crown", not you). Yet in England you can hunt private land (farmers fields, since those are not public lands) till you're blue in the face, and only need to give caches or unique things for the archie's to assess, as they don't care about individual coins. Same for Mexico: the laws are *realistically* only applied to the Mel Fisher type salvor things, or trying to export gold bars out of the country that you "found" in the pyramaids, etc.... Ie.: casual beach-combing has never been looped into the same "govt. owns the resources" type verbage (unless you kept asking long enough and hard enough, I suppose).
And also, the same conclusions as this India thread have been reached about many European countries, when people read "dire sounding" verbage. For example, here's a link someone developed, years ago, about various European countries laws:
Law
Notice how nearly every single one of these, as dire sounding as it/they may be, continues to float words like "archaeological", "historical" and "antiquities". And with origination dates that pre-date detectors (at least for their origin). And thus in actual practice, modern coins, modern fumble fingers jewelry, etc.... may simply not be in the intended and practiced intent of those laws.
Yet even in some of those "dire sounding" countries, there are hobbyists. Even clubs and dealers, etc....
The reason is, I think it would be a little like if someone from Europe were getting ready to vacation in the USA, if he were to ask enough questions, of enough federal archaeological lawyers here. He also might come away with the same impression that you "can't detect in the United States". Why? Because perhaps he reads ARPA. Perhaps he reads scary stories of certain state's parks. Perhaps he reads of Mel Fisher's legal woes, etc... I mean, if you couch answers in terms of Shiloh, Ghettysburg, etc.... (and some people even believe federal and state level laws subrograte down to county and city level afterall!), you could also come away with the impression that doom and gloom await you in the USA too. Such as been the experience of some folks getting ready to vacation to Mexico. They inquire ahead, and get a "no". Because perhaps whomever they asked is couching the answer in terms of export laws, raiding the pyramaids, shipwreck salvor stuff, "resources in the ground" laws, and so forth. So the md'r leaves the detector at home. Imagine the md'rs surprise, when they arrive at their Mexican beach resort, only to see other md'rs plying the beach. Hmmmm.
About 7 or 8 years ago, I had a detector for sale on ebay. The winning bidder was from one of those countries on the European list, with "dire sounding" wording. He was willing to pay the extra cost for cross-country shipping, so I went ahead and did the deal with this winning bidder. But my curiosity got the better of me, so I emailed him, sent him that link to Europe, and said "I thought metal detecting there was illegal?" He emailed back that verbage such as that, only applies to the federal level lands. So they hunt private farmer's fields, to their heart's contents (something that the link to the laws doesn't go into details about). Or .... he said ........ quite frankly ..... they're hunting so far out in the forests that there's no one around to "care" anyhow.