描述YouTube screenshot demonstrating Wikipedia fact-checking.png
English: YouTube uses Wikipedia as a fact-checking service. This partial screenshot of a YouTube video shows YouTube's placement of an alert box and link to Wikipedia article which may put the content of the video into factual context. This example has social significance because conspiracy theories about climate change were one of the motivations for YouTube to establish their service. The presenter in this YouTube video is en:Michael E. Mann, who is a scientist with mainstream beliefs on climate change but who was the target of major criticism as the originator of the en:Temperature record of the last 2,000 years and its famous illustration, the en:Hockey stick graph.