Four suburban Illinois teenagers were being held Tuesday on child pornography charges for allegedly producing a group-sex video of themselves and posting it to Twitter.

The youths, whose names were not released because of their age, include a 15-year-old girl and boys 14, 15, and 16. They were arrested Friday and charged with distributing child pornography online.

"The child pornography offense that was charged is in place for a reason, because we don't want to accept that type of behavior as a society. So I think it's making a strong statement, and I think it's important to do so to send the message to others: that kids shouldn't be involved in this type of behavior, and hopefully this will serve as a deterrent," Joliet Police Chief Brian Benton said.

After learning about the footage, the girl's mother contacted police about the March 24 video.

Local press said a hearing is set for April 13 to determine whether the youths should remain in custody. Punishment could range from probation to being detained in a juvenile facility until their 21st birthdays.