Ten teenage boys were arrested Thursday in Quebec in connection with their use of the app Snapchat, according to CTV Montreal. All of the boys are suspected of producing and distributing child pornography, thanks to photos obtained via Snapchat.

CTV reports that the boys allegedly lured seven girls into sending pornographic photos to them, using the fact that Snapchat messages self-destruct as bait. What the girls apparently did not know (or trusted would not happen) is that there are a slew of ways to preserve Snapchat messages. Would-be preservers use secondary devices, other apps, or fairly simple hacks to recover the photo files from the receiving phone’s flash storage.

Twenty investigators and “dozens” of officers have been pursuing the case ever since a staff member at a high school in Laval, where the boys were arrested, noticed a boy looking at a risqué photo of a girl on his phone. The boy was sent to the principal’s office, where he revealed that many boys had access to these photos that had spread to two other schools.

The boys are set to appear in court on charges of the production, possession, and distribution of child pornography.