7.30's Mark Willacy goes inside the covert sting operation that brought down a global paedophile ring, including its South Australian ringleader. Read more here: http://ab.co/1WRuXDW For more from ABC News, click here: http://www.abc.net.au/news/ Subscribe to us on YouTube: http://ab.co/1svxLVE You can also like us on Facebook: http://facebook.com/abcnews.au Or follow us on Instagram: http://instagram.com/abcnews_au Or even on Twitter: http://twitter.com/abcnews