Can You Copyright a Joke?

Reader AnalogDiehard writes: Writer Alex Kaseburg has filed a lawsuit against TBS and Time Warner alleging that jokes recited on the Conan O'Brien show were stolen from his blog shortly after they were published. The case gets heard in August and could create new protections in a legal forum in which there is little precedent or clear definition in what defines a joke as "original" and subject to legal protection, especially in an industry where theft of humor occurs on a regular basis. But the outcome of any judicial decision opens a big can of worms and raises serious questions: Will YouTube videos get shut down from DMCA notices citing copyrighted jokes? Will compliance staff have to be retained to ensure that their magazine or news article, TV show, movie, or broadway act is not infringing on copyrighted jokes? Will copyrights on jokes get near-perpetual protection like the controversial Sonny Bono Copyright Extension Act? Will people be able to recite limericks without fear of infringing? Will tyrannical politicians copyright critical jokes to oppress freedom of speech? Will legal cases be filed arguing that a comedian's joke(s) bears too much similarity to a copyrighted joke recited decades ago? Will girl scouts be free to tell copyright jokes around the campfire?