In "The Cult of the Amateur: How Today's Internet is Killing Our Culture" (2007), the media critic Andrew Keen uses the slogan "two plus two equals five" to criticise the Wikipedia policy allowing any user to edit the encyclopaedia — that the enthusiasm of the amateur for user generated content, peer production, and Web 2.0 technology leads to an encyclopaedia of common knowledge, and not an encyclopaedia of expert knowledge; that the "Wisdom of the crowd" will distort what society consider to be the truth.