Comedian Ari Shaffir performs at the 2015 Bonnaroo Music and Arts Festival in June in Manchester, Tenn. Shaffir has said fellow comedian Carlos Mencia stole his joke about who would build a fence on the U.S.-Mexican border. Copyright on jokes is difficult to prove, and it turned out two other comedians had made similar jokes as well. John Davisson/Invision/AP hide caption

itoggle caption John Davisson/Invision/AP

Everyone knows how to sing "Happy Birthday to You." But performing the song in movies or on TV requires payment of sometimes hefty licensing fees. Now the song is at the heart of a lawsuit. iStockphoto hide caption

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The e-book's original cover image was used without permission, according to a lawsuit filed against Amazon, Barnes & Noble and Apple. Amazon via The Daily Beast hide caption

itoggle caption Amazon via The Daily Beast

cover McSweeney's hide caption

itoggle caption McSweeney's

Nike-owned Converse, the company responsible for the Chuck Taylor All Star shoe, is suing to stop other shoemakers from copying what it says are distinctive elements of its design. Grant Halverson/AP hide caption

itoggle caption Grant Halverson/AP

This 2011 image taken by a crested black macaque in Indonesia has ignited a debate over who owns the photo. The camera's owner says the image belongs to him. In its new manual, the U.S. Copyright Office disagrees. David J Slater/Caters News Agency/Wikimedia Commons hide caption

itoggle caption David J Slater/Caters News Agency/Wikimedia Commons

Law professor Lawrence Lessig has reached a settlement with an Australian record label that tried to sue him for infringement. Neilson Barnard/Getty Images hide caption

itoggle caption Neilson Barnard/Getty Images

A law designed to protect copyrights on music and movies put digital locks on all sorts of things. iStockphoto.com hide caption

itoggle caption iStockphoto.com

A 3-D printed bust of Yoda is one of the more popular digital designs shared on Thingiverse. Courtesy of StruveDesigns.com hide caption

itoggle caption Courtesy of StruveDesigns.com