A minor example, but one that will stick:

North Korea has told Hyundai Asan it will halve the number of South Korean tourists allowed to visit the North’s Mt. Kumgang to 600 a day…

That is from an average of 1,000-1,200 tourists per day. Why would North Korea do this?

The move apparently comes in protest at the South Korean company’s decision to oust its vice chairman Kim Un-kyu despite objections from Pyongyang… At a meeting, the North made it clear it was miffed that Hyundai went ahead with the ouster of its vice chairman despite North Korean pleas to let the embattled executive stay. An internal inspection had found Kim guilty of corruption, and he resigned at a board meeting on Aug. 18.

North Korea, ever a case-study in how a nation can act contrary to its own interest, just sent a major signal to any foreign (i.e., non-South Korea) firm that entertained investing there; we will (attempt) to meddle with the internal workings of your company.

They may as well piss on the shoes of arriving potential investors.

UPDATE: A response from South Korean media;
Chosun Ilbo: ‘N. Korea Can’t Meddle With S.Korean Businesses‘
JoongAng Daily: ‘Unjustified interference‘
Korea Times: ‘North’s Childish Behavior: Do Not Interrupt Mt. Kumgang Tour Project!