This is a compilation of NekNominations. The premise is that you drink an alcoholic beverage — or, as they say in Australia, "necking" — and then nominate someone else to do the same.
According to Twitter, references to "necking and nominating" started, albeit slowly, around three years ago.
It's likely it was started as a response or an off-shoot of a similar drinking challenge called "icing" which picked up steam in the U.S. around the same time.
The Daily Mail linked the sudden increase in popularity to London Irish rugby player Ross Samson. Samson nominated his entire Facebook newsfeed on Christmas Eve.
Hundreds of Facebook pages sprung up, allowing users to nominate each other faster. Also, mentions of the game exploded on Twitter.
He claimed it was a relatively common Australian drinking game:
VICE: Who created neknomination?
Jay Anthony: A group of guys in Scotch college in Western Australia. One of them skulled a beer and said to his mate, "You're next." It became a trend, and then when my page went up it kind of snowballed. It moved through Australia, then New Zealand, and now it's even gaining traction in Europe.
The nominations keep getting more intense as the trend spreads around the world. One Facebook user mixed and drank a cocktail he claimed included cider, eggs, battery fluid, urine and three goldfish.
The first reported death was a 22-year-old DJ from Dublin named Ross Cummings. He was nominated and then found unconscious after trying to chug a large cocktail.
Less than two days later, it was reported that Irish teenager Jonny Byrne drank a massive cocktail and jumped into a river, only to drown.
Stephen Brooks' death was the third to be connected to NekNominations. The 29-year-old Welsh man was found dead in his home after downing a pint of vodka.
Isaac Richardson died earlier this month after drinking a concoction of wine, whisky, vodka, and beer. The young man lost consciousness two minutes after downing the drink.
Most recently, Bradley Eames, a 20-year-old from Nottingham, England, was found dead days after he uploaded a video of himself drinking gin and teabags. His cause of death is still officially unknown.
In light of the recent deaths, rugby player Ross Samson has started to distance himself from the game. Though his now-private Twitter account still mentions it.
The game doesn't appear to have taken off in the U.S. as it has in the UK or Australia, but there are those who have tried it.
Facebook makes it tough to track, but there is a game picking up steam on YouTube with the same rules called The 1-Pint Challenge.
According to The Guardian, Ireland's communications minister, Pat Rabbitte, requested Facebook start banning NekNomination content. The social network has no current plans to do so, however.
Facebook said it aims to enable people to share freely while protecting the rights of others.
"We do not tolerate content which is directly harmful, for example bullying, but controversial or offensive behaviour is not necessarily against our rules. We encourage people to report things to us which they feel break our rules so we can review and take action on a case by case basis.
We also give people the ability to remove themselves from an uncomfortable conversation through tools such as untagging and blocking."