The increasing visibility of a wide range of militia and vigilante groups has repeatedly caught local communities and national leaders off guard.
For many Americans, law and order has long been as much a private matter as something for the government to handle.
The US has a centuries-old tradition of killing black people without repercussion – and of publicly viewing the violence. Spreading those images can disrespect the dead and traumatize viewers.
Cyber security firms have sparked a revolution similar to the spread of private police forces.
Nigeria is on the verge of passing a law to criminalise rampant mob lynching. Other countries have tried to do this and failed.