It was heartbreaking to hear.

As New Jersey 101.5 News Director Eric Scott, Child psychologist Dr. Steven Tobias and State Police Lt. John Pizzuro explored how to keep children safe from online predators in a special town hall presentation Wednesday night, one theme kept recurring — parents need to be involved in their children's online activity.

Teens can't be expected to always make responsible decisions, Tobias said.

It's one thing when a psychologist says it, when law enforcement says it. It's one thing when it's a matter of broad principle. It's another to hear from a parent still struggling and overwhelmed.

Just this week, caller Liz from Blackwood said, she was on her 14-year-old daughter's computer. Her teen is artistic, but introverted. She enjoys her time online.

"A chatroom came up," Liz said, telling Scott she'd be on an art site her daughter uses. "And it was filthy conversation."

Liz did what most parents would: "I said, 'This is her mother. She's a minor. If you contact my daughter again, I'll call the police."

"I didn't expect any response," Liz said. "And I got a paragraph response ... how if I was a better mother, my daughter wouldn't be doing this, and she wouldn't be on the computer."

But the person on the other end of the chat — and Liz is sure he's an adult, based on her own conversation — didn't come out of nowhere. He and Liz's daughter have been in touch for more than a year, she said.

"She really thought shis guy, this person, is her boyfriend, her love. I don't know how to convince her," Liz said. "She thinks because they were talking for a year, this person is her boyfriend, her love."

It's not an uncommon occurrence, Tobias said — but rather a demonstration of the poor judgment teens can be prone to demonstrate, and the reason their parents need to be involved in their lives online and off.

The solution he suggests: Monitor your kids online. But you won't catch everything.

"Also talk to them about values," Tobias said. "(Tell them' 'The quote-unquote friends you have over the Internet aren't your friends. These aren't real relationships that you're having.'"

Watch the full town hall below: