In 2012, Kurtzman's estate and Al Feldstein filed to reclaim the copyrights on their 1950s work at EC. The claim was based on changes to copyright laws made in 1976, in which copyrights sold could be reclaimed by the original independent creators at the time of copyright renewal. Under these laws Jerry Siegel's estate was able to regain rights to Superman from DC Comics, but work-made-for-hire creations by Jack Kirby and Marv Wolfman were found ineligible. The basis of the Kurtzman and Feldstein claims was that they were not employees of EC, but subcontractors.