The free online encyclopedia Wikipedia has been criticized since its creation in 2001. Most of the criticism has been directed toward its content, community of established volunteer users, process, and rules. Critics have questioned its factual reliability, the readability and organization of its articles, the lack of methodical fact-checking, and its political bias.
Concerns have also been raised about systemic bias along gender, racial, political, corporate, institutional, and national lines. Conflicts of interest arising from corporate campaigns to influence content have also been highlighted. Further concerns include the vandalism and partisanship facilitated by anonymous editing, clique behavior (from contributors as well as administrators and other top figures), social stratification between a guardian class and newer users, excessive rule-making, edit warring, and uneven policy application.