Children are increasingly being groomed over the internet for the sole purpose of online sexual abuse, research by a child protection watchdog suggests.
Only 7% of the 1,145 online abuse cases reported to the Child Exploitation and Online Protection Centre in 2012 involved people trying to meet a child.
Ceop said offenders may target hundreds of victims at a time, and described the abuse as an "alarming new trend".
The organisation said parents needed to talk to their children about the issue.
Peter Davies, chief executive of Ceop - which monitors child abuse online - said: "We've seen a drop in the amount of grooming with a view to meeting offline. That's still a risk but it's a diminishing risk.
"The growth area seems to be grooming, contact, and then sexual abuse purely online. We really need to make sure that young people are target hardened [sic] against that.
"It's amazing, the number of parents I meet who would not think twice about talking to their kids about just about anything else that is risky - but have a blind spot about online."
There were 1,145 reports to Ceop in 2012 relating to incidents of online grooming. However, only 7% of these related to attempting to meet a child offline, a drop from 12% in 2011.
Online sexual abuse is commonly conducted via webcams, instant messenger applications and social networking sites.
The research by Ceop and the University of Birmingham suggested physical contact did not appear to be a motivation for offenders who sought to abuse children in this way.
Ceop said that once initial contact is made, it "often rapidly escalates into threats and intimidation".
A Ceop spokeswoman said some offenders hack into the accounts of victims and say they will only get their account back if they do what the abuser tells them to do.
Thereafter the abuser makes more demands "so the victim often feels like they haven't got any control... and it ends up in this spiral of continuous abuse", she added.
Mr Davies said the "devastation" caused to young people's lives through online grooming could be seen on a daily basis.
"UK children can be targeted from anywhere and offenders will cast their net widely to target large numbers of children," he said.
Ceop's research highlighted the case of two brothers in Kuwait who targeted 110 children worldwide - including 78 in the UK - forcing them into performing sexual acts online.
The pair were jailed for blackmail offences last December following a Ceop-led investigation.
Ceop said the pair pretended to be someone the children already knew on social networking and instant messaging applications. They would trick victims into giving them online passwords before threatening them into engaging in sexual activities via webcam.
There was no evidence of an offline meeting with victims ever being a motivation, Ceop said.
Ceop also said that instant messaging on mobile phones was used by paedophiles to contact children in about third of the reports of grooming it saw in 2012.
While smart phones were increasingly popular among 12 to 15-year-olds, more than two-thirds of them do not have parental controls installed, it added.
Ceop's chief executive said parents and carers had a duty to ensure their children remained safe online.
Claire Lilly, of children's charity the NSPCC, said there had been a sharp rise in young people contacting its Childline help service about being approached online.
She said: "What is apparent is that parents and carers can make that vital difference in whether or not a child becomes a victim of these ruthless predators online.
"The internet is part and parcel of young lives... we can talk to young people and educate them on staying safe online just as we do about stranger danger or drugs."