The country - which has the fourth biggest population in the world - has approved new restrictions designed to protect young people online. And with high levels of internet use among its more than 284 million people, the ban could have a big impact. Since Australia brought in the world's first ban of under-16s on social media in December, a succession of other countries - including Spain, France, Austria, Denmark, Finland, Greece and Italy - have said they plan to do the same.