Fair Use

Fair use needs to be a permissible reason to avoid libel suits. I don't really see how either of these cases represents libel, but I guess the author could be offended about having his characters malformed. Most parodies are unflattering of their source material, but sometimes this message is the purpose of the parody. It's very difficult to parody a private figure and if I remember correctly, public figures have a much harder time proving libel. Main point, if all parodies were open to libel suits...we'd probably never have them.