Originally Posted by
mahohmei
What happens if you're leaving Shengen and you refuse to produce your passport--or they find out you overstayed your visa or were otherwise in the area illegally?
Then you might be blacklisted and prevented from entering again. If you don't have a passport you won't be able to fly, if leaving at a land border, then perhaps it might be different if you can prove that the receiving country will accept you.
North Korea has exit controls too.
As does every country in the world except the US, Canada and the UK.