Plagiarism is the illicit reproduction of another person's Intellectual property, especially written content, for presentation as one's own. The definition of the term is often expanded to include not just verbatim copying but also "close imitation."
Plagiarism is a large and growing problem online as the number of content producers proliferates and unscrupulous individuals seek the easiest way to get content online. Content mills, for example, pay writers very little so some contributors appropriate content and represent it as their own work. Autoblog owners are also frequent abusers of copyright law.
See also: fair use