Australia’s controversial new law barring under-16s from social media is one of the toughest crackdowns yet on platforms including Facebook and TikTok as governments worldwide grasp for ways to protect children from harmful content.

The new law will deliver a message to tech companies to "clean up their act," the country's prime minister has said.

Technology giants respond to the government's new social media laws banning those under 16, meeting the "rushed process" with "concern" and disappointment.