Not sure if laws are differing from region to region in the USA but, we built a house for a fellow, he quit paying for everything, we stopped construction and the legal proceedings started.

There was still about 5,000 in lumber left on the property, the home owner was using it to continue the construction.
My boss asked his Lawyer what to do, he said...its your lumber isn't it?

We went and took it and returned it to the lumber store. The guy was threatening from a distance, lol.