Social media are useful facilitators when recruiting hidden populations for research. In our research on youth and radicalization, we were able to find and contact young people with extreme ideals through Facebook. In this article, we discuss our experiences using Facebook as a tool for finding respondents who do not trust researchers. Facebook helped us recruit youths with extreme Islamic and extreme left-wing ideals. We conclude by discussing the benefits and limitations of using Facebook when searching for and approaching populations who are difficult to reach.