'Six degrees of Kevin Bacon' has been a thing since the mid 1990s: it's a game in which you try and connect any actor to Kevin Bacon via six degrees of separation. It all began when, one day, Bacon joked that he felt like he'd worked with "everyone in Hollywood".
The 61-year-old star is now using this quarter-century-old trope for good, telling people to stay at home because of the coronavirus pandemic.
He started the 'I Stay Home For' social media trend on Thursday, posting a video to Instagram imploring his followers to stay at home. "It saves lives, and is the only way we're going to slow the spread of this coronavirus."
"Every one of us has someone who is worth staying home for," the actor said, saying he's staying home for Kyra Sedgwick, his wife of 32 years.
"Since we're all connected by six degrees – trust me, I know – we can all work together to stay home and be safe."
Bacon then nominated six celebrities to also post about who they are staying home for: Jimmy Fallon, Elton John, Brandi Carlile, Kevin Hart, Demi Lovato and David Beckham.
So far, Elton John, Demi Lovato, David Beckham and Brandi Carlile have responded, each nominating people themselves.
To follow just one link in the chain, for instance, singer-songwriter Brandi Carlile nominated Ellen Degeneres, Dolly Parton, Harry Styles, Eddie Vedder, Pete Souza and Barack Obama.
Both Souza and Degeneres have replied: but just to follow Ellen's reply, she posted on Insta stories to say she stays home for both her partner Portia de Rossi, and for her own mother who is 89, as well as her mother-in-law and her nieces.
But she also said she stays home for "just basically everybody, because it's the safe thing to do".
She then nominated actors Jennifer Aniston, Courtney Cox and Leo DiCaprio, former first lady Michelle Obama and musicians The Weeknd and Bruno Mars.
At the time of publishing, none of those challenged had responded yet. But at least one of them is very likely to keep the chain alive.
Meanwhile, David Beckham nominated his son Brooklyn Beckham, celebrity chef Gordon Ramsay, TV host James Corden, nutritionist Rosemary Ferguson, footballer Gary Neville and football agent (and Beckham's best friend) David Gardner.
Watch their accounts to see the chain continue, and if you are soon nominated, you may yourself be just six degrees of separation from Kevin Bacon.