Does new media promote accountability in nondemocratic countries, where offline media is often suppressed? We show that blog posts, which exposed corruption in Russian state-controlled companies, had a negative causal impact on their market returns. For identification, we exploit the precise timing of blog posts by looking at within-day results with company-day fixed effects. Furthermore, we show that the posts are ultimately associated with higher management turnover and less minority shareholder conflicts. Taken together, our results suggest that social media can discipline corruption even in a country with limited political competition and heavily censored traditional media.