Three days ago on this very same thread, according to Monika Settlemyer, the mother of one of those arrested:  

 "however ex-boyfriends provided photos of ex-girlfriends, many were stolen off hacked phones by yet another teen," and 
"No one is taking anything away from the victims who's photos were stolen and dispersed without their consent nor should they. That is a horrid violation."

According to Sara Elizabeth Montero, also posted here three days ago:

"These pictures were not shared with consent. Many were taken by the girls and then stolen by Shea or Cooper who would steal their phones and send the pictures to themselves."

The defendants appear to be thieves.