The dark side of Black Friday
Americans are flocking to the shops for Black Friday, the bonanza US sales day held the day after Thanksgiving.
But its massive popularity - the term Black Friday has been used more than 2 million times on Twitter in the past 24 hours - has a dark side. The vast volume of shoppers has led to chaotic scenes and outbreaks of violence. Stampedes and shootings have plagued the day, resulting in four deaths and 56 injuries in the past five years.
There has been an online backlash against the day's rampant consumerism, to the extent of groups campaigning for a "Buy Nothing Day" to allow shop workers to spend more time with their families.
#BBCtrending investigates the darker side of the day.