All well and good for people to suggest Maria Altmann ought to have hung on to the Klimt paintings that were stolen from her ancestors by Nazis and recently returned. But “what if Ms. Altmann had decided to hold on to her Klimts? Once Nazi-looted art is restored to its rightful owners, the bills start coming in. Lawyers in some restitution cases may work pro bono, but their costs cannot be waived, and these can quickly pile up.”