In just three months, researchers from the Internet Watch Foundation (IWF) found more than 2,000 videos of live-streamed child abuse on the internet.
In 96% of those, a young person was on their own, most often in their bedroom or bathroom.
The study said grooming was often made to seem like a game, with the child persuaded to perform sexual acts after they had received a number of likes online.
Almost all of the victims were girls and all of the images had been redistributed on other websites.
One young victim, a 12-year-old girl, said she had repeatedly exposed herself on her broadcast stream, where she had 50 viewers.
However, she would stop broadcasting if she did not get comments or likes, because there was “no point” in continuing.
But, the higher the number of likes, the greater the victimisation, the study said.
Some 98% of the images were of children under the age of 13 and 28% were under 10.
The youngest was only three, the study said.
Susie Hargreaves, chief executive of the IWF, said: “The backgrounds in the videos we studied mostly showed that the youngsters were in very ordinary home settings.
“Critically, no adult appeared to be present in the images we saw.
“Therefore, it’s our belief that these children were being directed to abuse themselves and live stream the sexual abuse.
“This form of grooming is complicated and only possible because of the anonymity the internet offers.
“An offender may be, for example, a 40-year-old man.
“But by abusing a legitimate internet site to create a false profile, he could appear online as a 12-year-old schoolgirl.”
Study author Sarah Smith said: “Permanent captures from live streams showing children being groomed or encouraged to perform sexual acts now represent most of the new images and videos IWF sees.
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“This abuse can happen to any child who has access to live-streaming technology.
“All parents and carers should remain vigilant.”