North Korea has recently introduced a sweeping new law which seeks to stamp out any kind of foreign influence - harshly punishing anyone caught with foreign films, clothing or even using slang. But why?

Yoon Mi-so says she was 11 when she first saw a man executed for being caught with a South Korean drama.

His entire neighbourhood was ordered to watch.

"If you didn't, it would be classed as treason," she told the BBC from her home in Seoul.

The North Korean guards were making sure everyone knew the penalty for smuggling illicit videos was death.

"I have a strong memory of the man who was blindfolded, I can still see his tears flow down. That was traumatic for me. The blindfold was completely drenched in his tears.