THERE was drama in Dubai on Sunday night when Justin Bieber, the tantrum-prone popstrel, was grabbed by a fan.
He came from behind while the Beebs was singing "Believe" at the piano and tried to embrace him.
But a minder hurtled across the stage and wrestled him to the ground, knocking the piano off the dais.
It was initially unclear whether the teen dreamboat was underneath - fans could be heard shrieking "Justin! Justin! Oh my gahhhd…" - but soon he could be seen skipping across the stage, out of harm's way.
It was a reminder of how perilous things can be when you're performing up there.
As Robbie Williams found out in February 2001, in Stuttgart's Schleyerhalle stadium, when a 20-year-old fan, believing him to be "a clone", ran at him from behind and pushed him off stage.
Williams landed in a security pit. He wasn't badly hurt and returned for six more songs, while the fan was sent to a secure psychiatric unit.
Less fortunate was the prog-rock exponent Frank Zappa at London's Rainbow Theatre in 1971 when, during an encore, an audience member pushed him off the stage.
Zappa fell into the orchestra pit, which had a concrete floor; he suffered multiple fractures, head and leg injuries that put him in a wheelchair for six months, and a crushed larynx, which dropped his singing voice by three tones.
Noel Gallagher, the Oasis guitarist, encountered an unwelcome pusher while performing at Toronto's Virgin Festival in 2008.
Bang in the middle of "Morning Glory" ("Need a little time to wake up wake up…") a man rushed across and pushed Noel off stage into the audience.
He returned to finish the gig, despite having three broken ribs.
God knows what injuries the assailant sustained after being grabbed by security men (and Noel's brother Liam) and hustled out of sight.
Occasionally, an assaulted rocker (step forward, Keith Richards) has retaliated by bashing the intruder with a guitar. But one needs to exercise caution.
Two months ago, Randy Blythe, lead singer with the rock band Lamb of God, was standing trial for manslaughter in Prague, after a 2010 concert when he "violently" pushed a teenage fan, Daniel Nosek, off the stage.
Nosek later had surgery to reduce swelling in the brain but lapsed into a coma and died. Blythe faced a minimum five-year jail sentence, but was acquitted, because his actions "did not constitute a crime".
But it's hard to know exactly what the rules are when you're standing 10ft above the crowd, with 10,000 decibels blasting from behind you, 10,000 faces in front of you, and one envious little so-and-so determined to bring you down…
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