The country isn't alone in curbing social network use, joining the likes of the Democratic Republic of Congo, Iran and Turkey. While Sri Lanka's bans are momentary and ostensibly aimed at preventing already chaotic situations from getting worse, they share a common effect of chilling all online speech, not just extremists and misinformation, until the ban is lifted.

Facebook and other internet giants have taken their own steps to limit the spread of false stories, such as imposing limits on WhatsApp forwarding and image search tools that could help spot fakes. Sri Lanka doesn't appear willing to trust those measures, however, and may be particularly reluctant in light of violence on this scale.