The ARPA law has some teeth! (Archelogical Resource Protection Act)
Shiloh NMP (or is it NB) made a case in the last 5-10 years or so and the guy had to sell his house to pay the fine. He told us it was a $15,000 dollar fine!
How did I come to have this conversation? Said subject had a trophy deer head in his possession, which had been killed illegally, (unlicensed hunter), and had transported head across state lines. Another serious violation, the Lacey Act.