There was reporting last year about Facebook being a catalyst for spreading violence against the Rohingya in Myanmar.

Facebook owned Whatsapp also caused several so called Whatsapp lynchings in India based on rumors that were quickly spread via the app. Brazil's current president's campaign also used a succesful disinformation campaign via Whatsapp.

Measles cases are on the rise in many countries. A lot of nasty politics is appearing in non-English speaking countries which gets no publicity, but it's difficult to trace to Facebook.

Of course, Facebook is merely the carrier for these influences. Some are driven by hostile intelligence agencies, some by opportunistic chancers.