An interesting blog post by ReCreate explains the rationale that the Anne Frank Foundation uses to suggest that the copyright term for the Diary should extend to 2051.
There are several absurdities to this story. First, Otto Frank could have claimed co-authorship during his lifetime, in the decades between the publication of the diary and his death, but never appears to have done so. The Foundation could have claimed co-authorship soon after his death in 1980, but instead waited until just six years ago to seek copyright advice, seemingly motivated by the fact that the work’s copyright term is set to expire at the end of this year. It seems bizarre to allow the Foundation to now try to claim copyright on behalf of a man who never tried to do so during his lifetime, and which it never sought to do in the several decades after his death. This move appears solely motivated by the royalties the Foundation will lose when the work enters the public domain.
Additionally, as pointed out by Mike Masnick of TechDirt, “who in their right mind thinks that copyright was the ‘incentive’ necessary for Anne Frank to write her diary?”
[Anne Frank School Photo. This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author’s life plus 70 years or less.]