Internet users have become more cautious about their browsing habits in the age of Edward Snowden, according to a new study from the University of Toronto’s Citizen Lab.

After the former NSA contractor leaked details of the agency’s surveillance through PRISM and other classified programs, the study found, interest in topics involving terrorism and national security appeared to plummet, dropping from about 3 million views per month to 2 million afterward. Viewership increased slightly after 14 months, rising back to 2.5 million.

The study, authored by Jonathan Penney and forthcoming in the Berkeley Technology Law Journal, analyzed monthly views of Wikipedia articles on 48 topics. Those articles included topics like jihad, al Shabaab, Hezbollah, al Qaeda and nuclear enrichment.