Children as young as 14 are taking part in an online game that encourages them to deliberately vanish for up to 48 hours.
To take part kids must fake their own disappearance and have no communication with their family of friends for as long as 48 hours.
Points are awarded for every social media mention they receive while they're missing.
This means any concerned posts or appeals for whereabouts online only serve to encourage the kids to stay missing.
One County Derry mum told Belfast Live that her family was left with "unspeakable" anxiety from the "sick" competition.
Her 14-year-old child left home accompanied by others and was found by Police 55 hours later.
She said: “I was terrified they were dead or would be raped, trafficked or killed. But these kids just think it’s funny.
"There was not even a moment of remorse when my child was taken into police custody and when the police brought my child home, I could see posts of selfies from the police car.
“I’ve been told my child and friends are in the lead in this competition because they managed to vanish for 55 hours before they were discovered."
She added: “We got lucky this time.
"Another teenager may not be so lucky and I dread to think of the consequences that could bring about.”
An NSPCC spokesman told getwestlondon : “Children can find it difficult to stand up to peer pressure but they must know it’s perfectly okay to refuse to take part in anything that make them feel unsafe or scared.
“Parents should talk with their children and emphasise that they can make their own choices and discuss ways of how to say no.
“Keeping young people safe online is a major child protection issue of our generation and it is also vitally important that parents discuss internet safety with their children using tips and resources available from the NSPCC and others.”
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