Justin Bieber. (a href="http://www.wenn.com" target="new window">WENN.com)

GARDEN CITY, N.Y. - When Bieber fever hit a New York mall in 2009, one of his managers and a record executive were hit with criminal charges.

Now, the 17-year-old star has agreed to make a public-service announcement for an anti-cyberbullying campaign in exchange for those charges being dropped.

The case stemmed from an incident when thousands of his fans turned up at Roosevelt Field Mall to see the teen pop star sign autographs. Police had cancelled the event since parents were fighting with each other.

Bieber's manager Scott "Scooter" Braun and Def Jam Records executive James Roppo were charged after police said they refused to help disperse the crowd, and pleaded guilty to fire code violations.

On Friday, prosecutors told a judge that they are dropping those charges.

A law professor from New York's Touro College said that "legally, for him to be involved in the solution to dealing with the criminal charges against other people is extraordinary."

Added County District Attorney Kathleen Rice, "To have someone like Justin Bieber, who is emulated by kids his age across the world, educating people about the dangers of cyberbullying, that's invaluable."

Braun's lawyer was happy about the deal.

"We started the week by bringing bin Laden to justice and we're ending on a happy musical note."