The deliberate spread of fear and violence goes back hundreds of years.
These days, we aren't often told when a terrorist plot is foiled, but Brits still set off fireworks to remember the one they do know about.
To achieve independence, history says you should play a long game.
Why did a hacktivist collective like Anonymous repurpose the image of Guy Fawkes for its ubiquitous masks? A scholar looks at how a 17th-century English villain became the face of resistance.