From 10 December, social media companies will have to take reasonable steps to ensure that under-16s in Australia cannot set up accounts on their platforms and that existing accounts are deactivated or removed.

The government says the ban - a world-first policy popular with many parents - is aimed at reducing the pressures and risks children can be exposed to on social media, which come from design features that encourage them to spend more time on screens, while also serving up content that can harm their health and wellbeing.

A study commissioned by the government earlier this year said 96% of children aged 10-15 used social media and that seven out of 10 of them had been exposed to harmful content and behaviour. This behaviour ranged from misogynistic material to fight videos and content promoting eating disorders and suicide.

One in seven also reported experiencing grooming-type behaviour from adults or older children, and more than half said they had been the victims of cyberbullying.

What platforms are affected?

The Australian government has so far named ten platforms to be included in the ban: Facebook, Instagram, Snapchat, Threads, TikTok, X, YouTube, Reddit and streaming platforms Kick and Twitch.

The government has said it will continue to review the list of affected platforms, and will consider three main criteria when doing so.

These comprise whether the platform's sole or significant purpose is to enable online social interaction between two or more users; whether it allows users to interact with some or all other users; and whether it allows users to post material.

How will the ban be enforced?

Children and parents will not be punished for infringing the ban - it is social media companies who are charged with enforcing it, and they face fines of up to $49.5m (US$32m, £25m) for serious or repeated breaches.

The government says these companies must take reasonable steps to keep kids off their platforms, and use age assurance technologies - without specifying which ones.

Will it work?

Without a clear idea of what methods companies will be using, it's hard to say whether the social media ban will be effective - but concerns have been raised that age assurance technologies may wrongly block some users while failing to spot others who are underage.

Are there data protection concerns?

Critics have also raised concerns about the large-scale collection and storage of data that will be required, and its potential mishandling, as platforms try to verify users' ages. But the government says the legislation incorporates strong protections for personal information.

How have social media companies responded?

Social media companies were aghast at the announcement of the ban. They argued it would be difficult to implement and could push children into darker areas of the internet.

Do other countries have similar bans?

The ban on under-16s using social media is a world first, and other countries will be watching closely. Different approaches have been tried elsewhere, but nowhere has put a total ban on the platforms involved.

Will children try to get around the ban?

Teens interviewed by the BBC said they were opening new accounts with fake ages ahead of the ban. The government has warned social media companies it expects them to detect such accounts and remove them.