I remember the photo, which appeared here back during the 2008 election campaign. Anybody still got it?
Sorry, the article links to another one, which shows some of the photos here:
http://obamareleaseyourrecords.blogspot.com/2012/06/filmmaker-reveals-new-evidence-frank.html
Add to this the fact that Frank Marshall Davis was a porn freak and a self-confessed child molester, and it all ties in—though no absolute proof, of course.