I suppose it would largely hinge on awareness of where someone is actually walking. No one has any right to stop them from walking, but sometimes it happens just the same. That's the reality. Apart from that, some areas are also dangerous in terms of terrain and local wildlife. I remember a few years ago when a hiker got lost, so she wanted to set a signal fire to alert authorities to her location, and ended up starting a huge forest fire that burned thousands and thousands of acres.
No one would argue that she didn't have the right to go walking somewhere, but for Pete's sake, people should have some sort of plan depending on where they're going to walk. They should have awareness of the pitfalls, dangers, and risks they're taking if they decide to go walking in a particular area.