Their beliefs were extreme and sometimes downright dangerous. Yeonmi Park, 20, grew up in North Korea believing Kim Jong Il was a god who could work miracles and read her thoughts. But after eventually escaping and settling in South Korea, Yeonmi came to realise just how deluded she had been about North Korea. Tom Olsen, 39, is a former neo-Nazi from Norway who used to dress in clothes plastered with the swastika. But his hard-core, violent views were shaken to the core by a chance event in South Africa. Now he works with police to try to de-radicalise others. Lebana Ilich, 15, was born into a commune. She says she wasn’t allowed to have any toys and was disciplined harshly several times a day with a rod. She thought the outside world was the "work of Satan". But now she’s out. This week Jenny Brockie hears from people whose beliefs were extreme and sometimes downright dangerous. She finds out how their ideologies came unstuck and what the lessons are for de-radicalisation programs.