Mobile phone aps and webcams are increasingly used to groom children for sex.
The NSPCCs Childline service fears more and more youngsters are becoming victims of on-line abuse.
It counselled Northern Ireland children 164 times last year, but given that a quarter of children didn't say where they were from the true figure is probably higher.
NSPCC's Karen Walker has talked to around 21 000 pupils at 190 County Antrim primary schools in the last five years: