Please read Wikipedia about YOU & UGC
User Generated content ("UGC") is featured in TIME magazine's 2006 Person of the Year, in which the person of the year is "you", meaning all of the people who contribute to user-generated media such as YouTube and Wikipedia.
User-generated content is a similar phenomena to open source which encourages user-generated software. A key example of this is LINUX which is a user-generated operating system started in 1991.
TIME magazine's "person of the year" issue from Dec. 25, 2006 notes the comparison as follows:
"Car companies are running open design contests. Reuters is carrying blog postings alongside its regular news feed. Microsoft is working overtime to fend off user-created Linux. We're looking at an explosion of productivity and innovation, and it's just getting started, as millions of minds that would otherwise have drowned in obscurity get backhauled into the global intellectual economy."