It was meant to be a puerile prank, but this week a shocking number of fans seemed only too willing to get bloody for Justin Bieber.
Dozens of devotees, dubbed Beliebers, were duped via Twitter into cutting themselves in protest at the singer's alleged drug use after pictures of the prince of pop apparently smoking a joint went viral.
The Twitter trolls behind the stunt had taken their inspiration from an earlier prank, which asked fans to shave their head in sympathy for the star after they spread rumours he was suffering from cancer.
Nonetheless, after being tricked into parting with their hair, few could have anticipated some fans would still be encouraged to actually shed blood.
However, ever since the death of Rudolf Valentino in 1926, one should never underestimate the lengths to which some fans will go when it comes to expressing their devotion.
Even though the notion of modern celebrity was in its early days when 'The Great Lover' died aged just 31, it did not stop two women from attempting suicide outside the hospital where he had passed away. Worse still, a young fan flipped out in London and drank poison, while an elevator boy at the Ritz hotel in Paris committed suicide after covering himself with photos of Valentino.
Over a decade later, by the time Frank Sinatra hit the big time, the era of the celebrity obsession had truly arrived. Even so, the fanatical devotion of his fans, known as bobby-soxers, thanks to their rolled-down white hosiery that peeped above their shoes, still took New York City police by surprise. In 1944 a throng of hormonal adolescent girls desperate to see Sinatra smashed windows, trampled a passerby, and even, according to one report, overturned a car.
But even the celebrity obsession sparked the bobby-soxers pale in comparison to a gift Dolly Parton received from one fanatical fan.
"The note said, 'My name is Jolene, my momma has left me here and she wants you to have me'," recalled Parton. "Of course, we all freaked out! It wasn't like it was a kitten or a puppy dog!"
Over the coming years that same realisation would dawn on an increasing number of celebrities. Michael J Fox, for example, received 6,000 letters from one obsessive fan. And while most were filled with admiration for the pint-sized Hollywood heartthrob, some contained rabbit droppings and threatened to kill his pregnant wife.
Shockingly, about one-third of Americans suffer from celebrity worship syndrome, according to psychologists at the University of Florida. And while most exhibit their symptoms through an addiction to gossip magazines, the boffins believe about 1pc display "borderline pathological" behaviour, and are willing to hurt themselves or other people in the name of a star.
But for Michelle Falsetta, a 37-year-old personal trainer, imitation was the most sincere form of flattery when it came to showing her devotion to Jennifer Lopez. She was inspired so much by J-Lo's ample rear-end that she splashed out $7,000 on "gluteal augmentation", or what is more widely known as butt implants.
Identical twin brothers, Matt and Mike Schelpp, went even further in the surgical mimicry stakes by undergoing nose jobs, chin implants, gum lifts, dental veneers and jaw implants to make them look like Brad Pitt. Sadly they were the ones who got the bum deal after ending up looking more like Beavis and Butthead.
"Younger people are more vulnerable, more easily influenced and more prone to idolise people," says Dublin-based psychologist Colm O'Driscoll. "Generally it will be just a phase they go through.
"The problem is our fascination with celebrities nowadays is a very different experience than 20 years ago. We are still a long way off America, but we are definitely going in that direction."
However, O'Driscoll thankfully does not believe we will ever quite catch up because when it comes to Justin Bieber's US fan base, they take a lot of beating in the crazy stakes.
Apart from being duped into shaving their heads and cutting themselves, one became so obsessed with the singer she actually accused him of being the father of her three-month-old baby. That of course was despite the fact that they had never actually met.
Indeed, when it comes to a special kind of madness, it seems you can leave it to Bieber fans.