Parents who buy electronic gadgets for their children this Christmas have been warned about the risks of online grooming following an alarming rise in reported cases.
In 2014/15 ChildLine carried out a total of 378 counselling sessions about the issue - an increase of 42% on the previous year, NSPCC figures provided to the Press Association show.
Children who called the service described feeling trapped after being asked to perform sexual acts on webcams, send explicit images online or meet in person.
Predators trawl social networks and online gaming platforms popular with children, often using profiles suggesting they are a similar age to their victims, experts said.
Girls are particularly prone to the tactics, accounting for seven in 10 of the contacts to ChildLine about online grooming. Victims reporting their experiences were aged as young as nine.
With millions of children set to receive games consoles, smartphones and other internet-enabled devices as gifts this Christmas, parents are urged to take steps to ensure youngsters are safe online.
NSPCC chief executive Peter Wanless said: "The internet offers an amazing environment for children to be creative, explore their interests, play with friends, learn or socialise, but there are risks every parent buying enabled devices this Christmas should be aware of.
"Over the last year there have been numerous cases of children been groomed online with often tragic consequences. No one thinks it will happen to their child, but sadly adults who want to harm or exploit children can be extremely devious in the way they manipulate those they target.
"Some offenders even take a scattergun approach, trying to lure in hundreds of youngsters at a time."
He said parents have a "vital role" to play in keeping their children safe online.
"Just asking children what sites, apps and games they use could be a great way to start a conversation," Mr Wanless added.
The use of the internet by paedophiles has been a long-standing area of concern and the threat has escalated in recent years with increase in the number of youngsters owning internet-enabled technology, along with the proliferation of social media services.
The mother of an online grooming victim said: "A few years ago I thought that I knew everything about online technology. I used to use social media and chat rooms regularly.
"But things change so quickly and now I don't know that much and wouldn't know where to start with giving advice to my children on it.
"I was a strict mum anyway when it came to my girls going online but I'm even more strict now and make sure none of them have passwords on their phones."
Last month police watchdogs called for better training for call handlers after finding that the mother of a schoolboy killed by a teenager did not receive the support she needed when she rang to raise concerns he was being groomed online.
Computer engineer Lewis Daynes was jailed for life in January with a minimum of 25 years for the murder of Breck Bednar, 14, from Caterham, Surrey, who was found with a fatal neck wound at a flat in Grays, Essex, in February last year.
:: Tips on internet safety can be found at: www.nspcc.org.uk.