Tell your children they must never email, chat, or text with strangers and it’s never OK to meet a stranger in the real world.
Whoever they see or meet online is still a stranger, no matter how often they see them online.
More information (from UK sources)
www.nspcc.org.uk/preventing-abuse/child-abuse-and-neglect/bullying-and-cyberbullying
www.childline.org.uk/info-advice/bullying-abuse-safety/types-bullying/online-bullying/