For those wondering how and why the wealthy can acquire these types of clearly stolen property, theres a great report with associated podcast dicing into all the machinations and legal wranglings surrounding a piece of art that was stolen by the nazis.
For the most part the legal maneuvers likely would have stalled out if not for the leaking of the Panama Papers years ago which shed light on who owned which shell companies, and how, etc.
Heres the short version of the article, theres also a more in depth podcast: https://www.npr.org/2016/04/12/473856459/panama-papers-provi...