Almost 2,000 children have been investigated by police in the last three years for breaking laws used to crack down on social media abuse, offensive Twitter messages and online bullying.
New figures show children as young as nine are among more than 1,200 who have then been charged with a criminal offence or given a caution, warning or fine.
The Sky News investigation also found almost 20,000 adults were the subject of police probes for these offences, the equivalent of around 20 cases a day.
And the number of cases is on the rise – up more than 5% since 2011.
Sky News asked police forces how many investigations they had launched in the last three years under Section 127 of the 2003 Communications Act, which covers abuse on Twitter or other social media sites, in text messages or through nuisance phone calls.
New guidance issued last year raised the threshold for prosecution, but experts say the rise in the number of cases despite the stricter definition is the result of easy internet access via smartphones.
According to responses from 34 police forces, 6,919 people were investigated in 2011/12 under Section 127, including 744 children.
Over the three years, 1,932 children were investigated and 1,203 were either charged with a criminal offence, fined, cautioned or warned verbally. Of the 19,279 adults investigated over that period, 11,292 were subject to police action.
Four 10-year-olds and one nine-year-old in Tayside were given warnings by police.
While the number of children being investigated for online abuse is rising, the proportion of children using social networks is falling.
According to Ofcom research, 35% of 5-15 year olds have an active social networking profile – down from 42% in 2011 and 43% in 2012.
Meanwhile two thirds of adults have a social networking profile – a figure unchanged since 2012, according to Ofcom.