Keeping youngsters safe online is one of the biggest child protection issues of the modern world, campaigners have warned.
According to the NSPCC, young people are now experiencing new forms of abuse "on a scale never before seen".
The charity said that its latest research had found that abuse through mobile phones and the internet is one of the major issues facing young people today.
It suggests children should be given lessons in how to use the internet safely from as young as five or six, amid concerns that rising numbers of youngsters are being exposed to online pornography, cyberbullying and forced into sending indecent images to others.
See also: Parents warned of online abuse
More top news
The 67-year-old is the most senior Roman Catholic cleric in the world to be convicted of covering up child sex abuse.
Mr Trump said Kim Jong Un had not met unspecified “conditions” for the summit.
Lava has destroyed a building near the plant in Hawaii.