Easement revisited

I posted a few days ago about about Metallica lead singer James Hetfield and his desire to enclose his property for the purpose of building a house and a studio on it. TPS law consultant Dana Johnson initially mentioned that there may be an "issue of implied easement" with regards to the trails to which Hetfield has now restricted access. As the story spread and other people commented, many other people felt the same way.

There's two issues here, positive and normative. On the positive end of things, that's what the law reads. From what I gather, people have been using these trails for years, and the law allows for continued use. Seems pretty cut and dry; I'm guess if enough people force the issue, he'll have to allow access. I don't know the caveats of the law, nor the case...Dana could provide more legal insight if needed, as always.

But on the normative end of things...what?! Property rights are only property rights under certain circumstances? The only saving grace on the economic end of things is that most (all?) easement cases should be pretty easy to anticipate, so uncertainty isn't rampant. But there will still be borderline cases where there is some element of the unknown-- property values fall, investment falls, time horizons shrink, and all the goodies that come with these effects.

I'm thinking-- again, Dana knows more than me-- that this law is rooted somewhere in common law. I'm curious where it evolved from. Note also that the issue of implied easement can only exist under a system of land allowed for public use.