ANother relevant academic article:
"Chilling Effects: Online Surveillance and Wikipedia Use"
«This article discusses the results of the first empirical study
providing evidence of regulatory “chilling effects” of Wikipedia users
associated with online government surveillance. The study explores how
traffic to Wikipedia articles on topics that raise privacy concerns for
Wikipedia users decreased after the widespread publicity about NSA/PRISM
surveillance revelations in June 2013.»
This study has been covered by various articles in the press, here's for
example one from "The Intercept" by Glenn Greenwald:
«New Study Shows Mass Surveillance Breeds Meekness, Fear and
A newly published study from Oxford’s Jon Penney provides empirical
evidence for a key argument long made by privacy advocates: that the
mere existence of a surveillance state breeds fear and conformity and
stifles free expression.