North Korea (DPRK) run concentration camps for convicts of its nation. In these highly secret camps, located mostly in the mountains of the country, prisoners are treated in the most inhumane ways, and this has been happening since longer than I have been alive.
There have been many attempts by human rights groups to gain permission to investigate these camps, but the North Korean government has always turned down these requests.
Therefore, I believe that it is necessary that the United States of America's government intervene, and stop these disgusting crimes, by means of force if required.
For more information on these camps, I would highly read 'Escape from Camp 14' by Blaine Harden. There is also a film for this book, however, detail is explained more graphically in the book.