Political and business leaders worldwide are turning against social media giants, in the wake of the Christchurch terror attacks.

Representatives from Facebook, YouTube-owner Google and Twitter are meeting with the Australian Prime Minister this afternoon, where it's expected they will be threatened with new restrictions and 'significant' penalties.

Ahead of the meeting, Scott Morrison said we need to prevent social media platforms being weaponised.

Morrison has already said he wants to put a multi-country social media crackdown on the agenda for June's G20 meeting.

Meanwhile New Zealand's biggest advertisers are stepping up their boycott of Facebook advertising, writing a joint letter calling on the international advertising community to join the action.

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