A group of message board users who act in concert to have other people's posts deleted by means of specious complaints to the moderators or admin without themselves participating in the debates at all. These folk know better than you
what you should read or write!
The concept of the "Dictatorship of the Censortrolliat" is inspired by Karl Marx's concept of the "Dictatorship of the Proletariat". Both are unpleasant examples of anti-democratic, coercive behaviour.