United Continental Holdings has sued a Canadian professor who maintains the 15-year-old complaint website Untied.com, which airs complaints from disgruntled United Airlines passengers and employees. United says it isn't trying to shut down the site, but just to protect its intellectual property. They think their customers could be confused and not realize that untied.com is not an official UA site. This despite the fact that to view the site you have to click a popup that states " This is not the website of United Airlines. This site exists only because of the airline's outright hostility toward its passengers and many of its employees."