Guy, or User:JzG, is an influential administrator at Wikipedia. A link from his Wikipedia talk page shows that his real name is Guy Chapman. Guy appears to have replaced William M. Connolley as the chief enforcer of Wikipedia's alleged neutral point of view. Many conservatives regard Wikipedia's "neutral point of view" as a liberal point of view, see Examples of Bias in Wikipedia.
Guy's dogmatic views on subjects including anthropogenic global warming and vaccination have led some Wikipedia editors to criticize him for advocacy. On 1 April 2016 Guy proposed to ban editor Conzar from editing the article Vaxxed, whioh describes a film about the controversial work of Dr Andrew Wakefield. Conzar was simply trying to uphold a neutral point of view but he was banned from editing all articles on vaccination on 4 April 2016.
The website Skeptical about skeptics has an article about Guy.