Australia said on Wednesday it will add YouTube to sites covered by its world-first ban on social media for teenagers, reversing an earlier decision to exempt the Alphabet-owned video-sharing site and potentially setting up a legal challenge.

Australia will impose a social media blackout for children under the age of 16 to tackle a growing mental health crisis among young people. But will the ban be effective?

YouTube will be included in Australia's world-first social media ban for children under 16, after the government ditched a previous exemption for the platform. The video sharing site was set to be excluded from the ban - which will limit TikTok,