This is a phenomena of mob violence which has been stoked up by individuals and social media.
PSNI Chief Constable Matt Baggott added it was fortunate nobody had been killed or seriously injured last night, and he praised police for doing a "magnificent" job.
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We are set to enjoy some sunshine after all that ice, snow and frost - albeit with temperatures still low.
The woman who was raped by Ched Evans has been forced to move house five times since being identified on Twitter, her father has said.
After ice and snow, a more dry and settled picture across the UK today - but it's still set to be chilly.