CHICAGO (CBS) — Parents in the Beverly, Morgan Park, and Mount Greenwood neighborhoods said they learned some eye-opening lessons Thursday night, when they attended a community meeting organized by police and the local alderman, in response to recent sexting incidents involving children.

Ald. Matt O’Shea (19th) said some parents appeared visibly shocked by what they heard from a Chicago police detective who specializes in online crimes.

“It was an awakening for many parents,” he said.

O’Shea organized the meeting in response to a rise in sexting among teenagers. He cited the recent case of a teen girl who took a nude picture of herself, and shared it with her boyfriend on Snapchat. He promptly shared it with friends, and since then it has continued to be shared with other students.

He was blunt in his assessment of how many parents oversee their children’s social media and other online activity.

“They need to do a better job of being parents, not their kids’ friends,” he said.