Here are our favorite reactions, from the wildly funny to the incredibly supportive:
Rainn Wilson: “I’m starting to miss the young, adorable, mop bucket peeing, house egging & strip club raging Bieber of 2013.”
Zach Braff: “Who amongst us hasn’t drag-raced a Lambo in Miami on pills? #FreeBieber.”
Seth Rogen: “All jokes aside, Justin Bieber is a piece of s**t.”
RuPaul: “Condragulations, your son is a woman! @RuPaulsDragRace Justin Bieber's official mugshot has been released.”
Jason Biggs: “50 in a 30. Jesus, Bieber even drag races like a p**sy.”
Jimmy Kimmel: "Just when the streets are finally safe from Lindsay Lohan, Justin Bieber was arrested in Miami Beach early this morning... and he's in trouble with his grandparents for not stopping by to visit while he was in town,"
Jimmy Fallon: "He's facing a pretty stiff penalty. They're saying he could get up to two years of being his own neighbor, which is just awful. It's just awful. You don't want that.”
Lady Gaga: “We may not understand everything celebrities do because there's only so much we see, but Justin and Beliebers were 'born this way' too. Let's spread love and compassion to Beliebers today. That is what we are all about."
Ariana Grande: “we're all human and we all have great amounts of pressure on us. when someone's hurting, be there. we could all use a little more compassion.”
Scooter Braun: "@justinbieber love you and i will act in the manner of someone who truly cares. that is all I have to say. thanks for all those concerned.”
To see how Selena Gomez reacted to paparazzi questions about Justin, watch the video below (at the 5 minute mark):