It doesn't matter if a public figure has been out of the spotlight for years, the paparazzi is going to find a way to bring them back. The general public doesn't always recognize a star when they see one, but if a single person calls attention to the star's presence, then mayhem ensues. It's part of the life of living in the spotlight and having an iconic reputation.
Yes, I believe that Justin Bieber is targeted by people because he is an extremely famous and wealthy person. Individuals are more likely too incite him because they know that they can sue him and get money from him in court. That being said, Justin Bieber needs to comport himself better and understand that this is the price of being famous.
Justin Bieber is a celebrity that wants to be in the spotlight. He is a very famous celebrity that often gets in trouble or causes some type of controversy. When he gets involved in something like a brawl at an NBA game, the media is going to consider this a newsworthy story. Both fans and detractors will be sure to talk about it. In short, Justin Bieber is a well known celebrity, not a private citizen; therefore, he is not targeted unfairly by people.
Justin Bieber is one celebrity out of many hundreds of celebrities. He is no more targeted than any other person who is famous. How he reacts to his fans or people who are not his fans is his responsibility. He must understand that a certain amount of heckling or dislike comes along with being a celebrity and how he handles that is for him to decide. However, if he decided to become violently involved it is unfair to say then it's not his fault and he is targeted. He has the ability to walk away just like everyone else.