Shannon brought her 18-year-old daughter, Ryann, to Dr. Phil because she claims Ryann has created fake online personalities, and has been sexually active with some of the men she’s met online.

While Shannon says she fears for her daughter’s safety, Ryann insists she knows how to stay out of trouble.

“I’m smart and careful with my actions,” Ryann says.

WATCH: Mom Claims Teen Is Catfishing Boys Online: ‘My Daughter Is A Pathological Liar!’

However, Dr. Phil cautions the teen about the dangers of creating misleading online profiles.

“You can go online and present yourself as something you’re not, and manipulate these guys, and what’s going to happen is you’re going to get in this relationship and they’re going to find out that you’ve manipulated them,” Dr. Phil says. “They’re going to find out that you’ve lied to them. They’re going to find out that you’ve tried to upset them, that you’ve tried to set them up – and they’re going to get hugely pissed.”

WATCH: Teen Denies Mom’s Catfishing Claims: ‘My Mom Thinks I’m The Devil’

Watch the video above as Dr. Phil sends a powerful message to Ryann – and tries to warn her about what may happen when men realize they’ve been lied to online.

This episode of Dr. Phil airs Thursday. Watch more here.