But on the other hand, it really isn't "allmansrätten" either. (I am from the US and live in Norway - and norway has the same sort of laws). Here in Norway, you can simply camp for a night in some unused wooded area or a field that is obviously not used. In the US, you can get arrested for doing such a thing. Nature isn't something that is free for everyone to enjoy, but rather, it is the property of whoever owns the land even if there is no barrier or signs to alert you otherwise.

How often that is enforced varies. My parents owned land and generally didn't care, though they wanted hunters to alert them first so the could keep themselves safe. Many area residents didn't care if a couple people were walking in their woods - but don't get the idea that you could camp there without law enforcement being called unless you had express permission of the landowner.