The Lacey Act requires "Due Care"
A few episodes ago when I talked about CITES, I was clear to say that it has no enforcement body and that is up to the governments of the signing countries. Well the Lacey Act is the teeth to enforce things like CITES.
In short the Lacey Act and the US Fish and Wildlife Bureau interpret laws from the origin of the lumber and determine if the material is legal. Certainly this means it was harvested legally from legitimate concessions and following concession plans. But where things really matter is in the transformation of the material and how much is required by law in the local state/province/county/etc. If a village in Africa says you can fell the tree but it must be sawn into boards, then buying a log is illegal and you are in violation of the Lacey Act.
That is scratching the surface of the issue but at its heart, the Lacey Act wants us to ask questions and exercise "due care" when importing and trading any lumber. Find out about the origin and know the local laws that apply to that material. And DOCUMENT everything!