The Baby hitmaker's public persona has taken a battering in recent weeks following a disastrous trip to the U.K. last month (Mar13), during which he kept young fans waiting until past 10pm for a concert and threatened to "beat the f**k out of" a photographer outside his hotel.
His increasingly erratic behaviour - which also included strutting the streets while wearing a gas mask - led to fears the teen idol is suffering a meltdown, and former 1990s pop star Knight has advised the singer to change his attitude towards the paparazzi if he wants to survive the fame game.
Knight tells British magazine Ok!, "I think Bieber's doing the right thing. Don't take any junk from nobody! No, I think lately Justin's had a bad time of it... But you have to learn to be like, 'Oh, that's funny, he's trying to bait me'. All the public see is him lashing out and it's: 'Oh, Justin Bieber's going crazy!' But that's not really the truth, he's just reacting to something... It would have got to us (in New Kids On The Block), but maybe we could recover better because we could talk to each other."