In his book Basic Rights (Princeton, 1970), Henry Shue argued that there is no valid distinction between negative and positive rights; his argument has recently resurfaced among so-called left-libertarians (otherwise also known as bleeding heart libertarians), a neologism if there ever was one. (I am tempted to start an association of no-nonsense libertarians to oppose them!)
The significance of the point needs to be stressed since if it were valid it would pretty much consign everyone to the status of a serf or involuntary servant. If we are all by birth obligated to serve other people first and foremost − which is what the doctrine of positive rights or natural entitlements alleges − our sovereignty would be a myth. We would once again be viewed as belonging to others; maybe not the king or pharaoh or czar but to the majority of the people who are ruled by a few "at the top."
The point Shue made is that since negative rights would require being defended in a society for them to have any concrete significance and since providing a defense of them would be the delivery of a service, having the negative right to, say, liberty or life, implies having the positive right to the services of the police and sundry legal authorities. And so the floodgates are opened: everyone must be made to pitch in to obtain this service, leaving it to some elite to administer such a system.
But not so then and not so now! First, having a negative right to liberty implies that others may not invade one, that a person may not be used against his or her will and not that the right must be defended. Of course, some will refuse to heed this fact and in the face of that it will be very useful to establish institutional protection of people's natural rights to life, liberty, etc. But first one has to have the right, contrary to some contemporary sophistries about the matter (such as Cass Sunstein's view that rights are granted by the government!). Then if violations are likely, predictable, etc., a means for protecting rights will most likely need to be found. For example, as the Declaration of Independence makes clear, governments are instituted to secure our rights but that may not be the only means available. (So if someone is powerful enough, no special agency would be required. One could just deter and fend off rights violators on one's own or with members of one's family, all, of course, in line with due process.)
But more likely in an advanced civilized society some would be hired to provide rights protection. The ensuing obligation to provide the specifics would be a matter of compact or contract. So citizens would then have a contractual or constitutional right to have their basic rights protected. And how this would be realized is an open question, part of jurisprudence. The issue here is only that people have the rights and those rights are negative. Then when they hire those offering the service of providing protection, then they will have the (derivative, secondary, non-fundamental) right to be provided with the protection.
It is not easy to know motivations for the obfuscation perpetrated by Shue and his current followers, including some who have the gall to call themselves libertarians; my guess is that once it looks like some basic positive rights − e.g., to be provided with rights protection − have been established, it is easy to move on to other positive rights, such as to health care, unemployment compensation, a good job, a nice home and so on and so forth, the entire array of entitlements that welfare statists advocate and that impose involuntary servitude on those who are in the position to provide them.
Thus what appears to be a case for a libertarian legal order has cleverly been turned upside down so as to support its opposite. It doesn't wash, however.