In FL, everything over 50 years old on state property/lands or under submerged state lands/preserves/greenways, etc. etc. it's a misdemeanor to pick up an artifact. If it's dug up that's a felony. Laws have changed. Archies and collectors no longer cooperate with each other as they did in the past when we had an Isolated Finds Program ran from the Museum of Nat'l History, Gainesville., along with fossil permits. You still have to have a fossil permit to collect on state lands or underwater any vertebrate material except shark's teeth, they are the exception because of the tourists. There are busts all the time on state properties and waterways. A fellow I know happened to post some pics . A "school teacher" met him at a show or somehow contacted him, befriended him and he was nice and gave her some stuff. She was no school teacher. They took every single thing from his house that was 50 years old or had any reference, like books, about artifacts, etc. He doesn't think he will ever get his stuff back and the charges I believe where eventually dropped, not without expense of money and life!@ He has not been the only one in this state or many other states.
On another forum I've been reading about a husband and wife "team" of wildlife officers who bust divers looking for artifacts. Guess it beats catching over the limit panfish..... All this info is freely available.
Remember, if you aren't doing anything wrong according to the law, you have nothing to worry about. If you live in FL, get your fossil permit.
There is a huge element of greed when it comes to collecting, as in other things... Young'uns, take my heed boom.