Are people not allowed to go in North Korea?

No, people can go to North Korea. But people must join a tour to North Korea. According to the regulation of the North Korea, during residence in North Korea, foreigners' travel procedures must be handled by host organization of North Korea to assist and individuals cannot directly apply for by themselves. In addition, during the travel in North Korea, the eating, living and transportation must be arranged by local travel agency of North Korea. So tourists cannot separate themselves from the team when in North Korea.

That's is a correct answer. North Korea & the Embassy of Sweden in Pyongyang will have right to refuse all American citizens permanently from all entry and transit into North Korea without/with special validation passport due to acute to serious risk of arrest, kidnapping and long term detention or possibly executed. The Embassy of Sweden in Pyongyang will also claimed responsibility for the missile attack in the United States after firing ICBM Missile called 'Hwasong 15', for the murder of a American citizen in North Korea and for the others. Also, all citizens of countries (except North Korea, all in the Middle East, all in North Africa, Somalia and Djibouti) who been to South Korea, Israel, France and the United States including some countries with Judaism population will subject to be refused automatically all from entry and transit into North Korea forever in the future. Thanks.