The reaction to the National Security Agency (NSA)’s secret online spying program, PRISM, has been polarized between seething outrage and some variant on “what did you expect?” Some have gone so far as to say this program helps open the door to fascism, while others have downplayed it as in line with the way that we already let corporations get ahold of our personal data.

That second reaction illustrates precisely why this program is so troubling. The more we accept perpetual government and corporate surveillance as the norm, the more we change our actions and behavior to fit that expectation — subtly but inexorably corrupting the liberal ideal that each person should be free to live life as they choose without fear of anyone else interfering with it.

Put differently, George Orwell isn’t who you should be reading to understand the dangers inherent to the NSA’s dragnet. You’d be better off turning to famous French social theorist Michel Foucault.

The basic concern with the PRISM program is that it is undoubtedly collecting information on significant numbers of Americans, in secret, who may not have any real connection to the case the Agency is pursuing. PRISM sifts through tech giants’ databases to cull information about suspected national security threats. However, since it uses a 51 percent confidence threshold for determining whether a target is foreign, and likely extends to individuals that are “two degrees of separation” from the original target, the chances are extraordinarily high that this program is spying on a significant number of Americans.

A citizenry that’s constantly on guard for secret, unaccountable surveillance is one that’s constantly being remade along the lines the state would prefer. Foucault illustrated this point by reference to a hypothetical prison called the Panopticon. Designed by utilitarian philosopher Jeremy Bentham, the Panopticon is a prison where all cells can be seen from a central tower shielded such that the guards can see out but the prisoners can’t see in. The prisoners in the Panopticon could thus never know whether they were being surveilled, meaning that they have to, if they want to avoid running the risk of severe punishment, assume that they were being watched at all times. Thus, the Panopticon functioned as an effective tool of social control even when it wasn’t being staffed by a single guard.

In his famous Discipline and Punish, Foucault argues that we live in a world where the state exercises power in the same fashion as the Panopticon’s guards. Foucault called it “disciplinary power;” the basic idea is that the omnipresent fear of being watched by the state or judged according to prevailing social norms caused people to adjust the way they acted and even thought without ever actually punished. People had become “self-regulating” agents, people who “voluntarily” changed who they were to fit social and political expectations without any need for actual coercion.

Online privacy advocates have long worried that government surveillance programs could end up disciplining internet users in precisely this fashion. In 1997, the FBI began using something called Project Carnivore, an online surveillance data tool designed to mimic traditional wiretaps, but for email. However, because online information is not like a phone number in several basic senses, Carnivore ended up capturing far more information than it was intended to. It also had virtually no oversight outside of the FBI.

As the Electronic Frontier Foundation told Congress in 2000, “Systems like Carnivore have the potential to turn into mass surveillance systems that will harm our free and open society…Once individuals realize that they have a lowered expectation of privacy on the Net, they may not visit particular web sites that they may otherwise have visited.” Writing in 2004, a group of scholars drew a straight line from this analysis to Foucault’s theory of disciplinary power. “Resembling the ever-present powers of the central watchtower in a prison modeled after the Panopticon,” they wrote “the very fact that the FBI has the potential to monitor communications on a website may lead Internet users to believe that they are constantly being watched.”

We know now that this hypothetical fear about Carnivore has become a reality, courtesy of the NSA. The more people come to see mass online surveillance as a norm, rather than something used only on specific subjects of investigation, the more they’ll tailor their online habits to it. Since people understandably don’t want the government looking at their private information, that’ll mean the internet will over time slowly become less of a place for vibrant self-expression. That should trouble anyone who believes that the best society is one in which people are most free to be themselves in whatever way they find most meaningful. In essence, that should trouble anyone committed to the basic liberal project.

Foucault’s point wasn’t that disciplinary power was intrinsically bad; the idea that, for example, pedophiles might be deterred from accessing child pornography for fear of state surveillance of child porn sites shouldn’t bother anyone. Rather, Foucault warned, disciplinary power was dangerous — used in certain fashions, it could be subtly corrosive of exactly the sorts of freedoms of expression and self-identity that liberal democracies purportedly protected absolutely. The NSA program, especially as itsbreadth becomes clear, is exactly the sort of overreach his work should warn us against.