Virtually all Internet users rely on some wiki since they are so prevalent, but did you ever wonder who owns the content? As a matter of fact as of October 2012 Wikipedia claims to have 23 million articles contributed by individuals around the world in 285 languages, and an "estimated 2.7 billion monthly page views in the U.S. alone."
Since wiki content is often controlled by open source licenses (which is generally free), the ownership of any wiki content is not entirely clear. But we may learn more about ownership based on a recent lawsuit filed by Wikitravel filed in August 2012 in a California state court against William Holliday, Holliday IT Services, James Heilman, and Does 1-10 for trademark infringement, violations of the Lanham Act (palming off trademarks), and unfair business practices. Although not a named defendant, the case is directed against Wikipedia's parent Wikimedia who allegedly want to take over Wikitravel.
If you want to learn more about wiki content ownership please read my eCommerce Times column entitled “The Mysterious Workings of Wikis: Who Owns What?"