Parents should forget about privacy issues and regularly check their children's smartphones and other electronic devices to prevent them from being victimised by predators.

The advice came from Jennifer Sellers, a grief-stricken mother from Pell City, Alabama, who found out that her 14-year-old daughter Sydney was a victim of an anonymous sexual predator. By then, it was already too late—her daughter had killed herself by hanging, CBN News reports.

Sellers said she and her daughter were very close, doing "everything together."

"I can't think of a single activity that we didn't do together except maybe her homecoming dance," she said.

But unknown to her, Sydney had secrets—secrets that revealed themselves only after Dec. 7, 2014, the day Sellers found her daughter hanging from a belt in her bedroom.

"It was such a shock that I opened the door and I said, 'Sydney, that is not a funny practical joke,'" she said.

Only it wasn't a joke. It was real.

At first, Sellers, who works as a child advocacy attorney, could not understand why her daughter would take her own life, especially since she had shown no signs of depression or trouble.

On the morning of that fateful day, Sydney even went to the church together with her parents.

Sellers later found out from her daughter's friends that she had been bullied at school. At the funeral home, they found cuts on her body, indicating that she had been cutting herself.

But this was not the family's most shocking discovery yet.

When Sellers and her husband checked Sydney's smartphone, they found out that at around the time of her death, Sydney was exchanging messages with a stranger using an app called "Kik."

They were talking about "erotic asphyxiation," or breath control play, which is the intentional restriction of oxygen to the brain for the purposes of sexual arousal.

The messages showed the stranger, who claimed to be a teenage boy, giving Sydney instructions on how such arousal could be done.

Sellers said the man that Sydney was chatting with the night she hanged herself could not be traced because the "Kik" app allows users to connect anonymously.

Sellers said she and her husband feel guilty for what happened to their daughter.

"I had gotten complacent," she admitted. "My husband had gotten complacent. She went to school, she came back, she did her work, she made great grades, we figure we were good there."

She urged parents to be more careful regarding the activities of their children. "You need to talk to your kids to find out who they are growing into as people," she urged.

"If you bought that phone, if you pay for that phone, I don't care what they say about their privacy," she said. "That is your property; you have a right to know what's on it. Search it out," she added.

She said this simple act could save a life.