Childline sees 'staggering rise' in online sexual abuse
Parents who bought their children laptops, tablets and smart phones for Christmas are being urged to talk to them about online safety.
Childline was contacted by 85 children in Wales about online sexual abuse during 2015-16 - contributing to a 24% rise in UK calls compared to 2014-15.
Online sexual abuse includes grooming, sexting and performing sex acts on webcams.
The NSPCC said it can cause children to feel "guilty and ashamed".
Some children contacted Childline because they felt "trapped by their situation", while others were being blackmailed or were considering meeting up in person.
A 14-year-old girl told Childline that she had met a man through social media.
"He told me I was beautiful and I felt that I could talk to him about everything," she said.
"He asked me for some topless photos which I didn't think was a big deal, so I sent him a few. But now he's turned really nasty and is threatening to post them online if I don't send him more.
"I'm really worried and embarrassed and I don't know what to do."
The NSPCC recommends parents talk regularly and openly with their children about online safety and learn how to spot signs of inappropriate behaviour and how to report it.
Head of NSPCC Wales, Des Mannion, said the internet can be a "fantastic place for children to socialise, explore their interests and learn" but parents should be aware that there are risks.
"In the last year we've seen a staggering rise in online sexual abuse, with many children turning to Childline when the situation has escalated," he said.
"Often groomers will use devious tactics to lure in young people and manipulate them into situations that leave them feeling frightened and ashamed."