I FULLY UNDERSTAND THAT THE German government wants to do everything as to fight against stolen art. But implementing due diligence guidelines is not the solution to this matter. You are punishing the honest collector, who happens to have invested his/her life collecting. A black market abroad will develop if you implement this law in Germany. Also what happens to all those collectors and auction houses who cannot proof where the item was purchased from or the owner left the country?

Fonte: