"If somebody hurts you, phone us and we'll help"

Spanish child abuse helpline launches poster campaign - with hidden message that only children can read.

A Spanish organisation that combats child abuse has received widespread attention for a new poster campaign featuring a hidden message that only children can read.

The Aid to Children and Adolescents at Risk Foundation (ANAR) worked with ad agency Grey Group on the innovative poster campaign, which uses a specially designed image only visible below a certain height - the average height of a child under 10.