National Security Agency whistleblower Edward Snowden is answering the Internet’s burning questions. Surprisingly, he was even gracious enough to answer my question: “What’s the worst and most realistic harm from bulk collection of data? Why do you think it outweighs national security?”

Snowden, who was granted protection in Russia from American prosecution, has been somewhat press-averse, only holding a few select media interviews. This time, he went directly to netizens to respond to President Obama’s big national security speech last week.

I posted the full response Snowden gave me below. In essence, he argues that the government’s bulk storage of our digital lives causes self-censorship and opens up the potential for severe abuse.

“Study after study has show that human behavior changes when we know we’re being watched. Under observation, we act less free, which means we effectively *are* less free,” he wrote.

He also notes that mass-spying, “enables a capability called “retroactive investigation,” where once you come to the government’s attention, they’ve got a very complete record of your daily activity going back, under current law, often as far as five years.”

I generally think Snowden is right, but the problem with his answer is that it doesn’t help us weigh these harms against the possibility of stopping a terrorist. There will most definitely be government abuse and Americans have already started censoring themselves. On the other hand, in the next 30 years, it’s possible this system could prevent one or two terrorists attacks, potentially saving dozens of lives and billions in economic losses.

As far as I’ve been able to find, the available “studies” that Snowden alludes to are only moderately helpful. For instance, one experimental study found that pervasively monitored participants were less likely to engage conversations that were neutral or critical of their peers. Personally, I do find myself watching my words over email since Snowden leaked the documents, despite the fact that the NSA doesn’t care much about me.

The idea of pervasive surveillance has been popular at least since hipster god-father and post-modern idol, philosopher Michel Foucault conceptualized the problems of an all-seeing authority that could randomly spy on individuals, ominously known as the Panopticon.

In practice, America’s former colonial master, the British, have had a public version of the Panopticon since the 1970’s, with their Closed-Circuit TV system (CCTV). CCTV does stop some crime, though it still happens. Many citizens simply forget that they’re being watched; It appears that humans cannot act on being paranoid 24/7.

In other cases, websites that offer more privacy, such as the Duck Duck Go search engine, have seen a spike in traffic. So, Snowden is correct, some people do change their behavior.

But, what is the actual impact of this behavior change? We still get to vote (and so do the British). There is certainly no end to criticisms of President Obama or anyone else in our government. Even if we watch our words, I haven’t noticed a difference in our democracy, for better or worse.

As to the government abuse of records, retroactively: yes, that’s a serious concern, which President Obama acknowledged in his last speech. Historically, our government likes to maintain hit lists and rogue agents like to abuse their powers for personal gain. It’s probably true that no system will ever be secure from the irrationality of a scorned lover.

Here the impacts are much more tangible. In the past, whistleblowers have had a major impact on the course of US history. Daniel Ellsberg’s release of the Pentagon Papers hastened the military withdrawal from Vietnam and saved many (many) lives. If we’re comparing body counts, it is as likely that the government could shut up a whistleblower who would otherwise stop a corrupt government initiative, as it is the number of those who could be the victims of terrorism.

Right now, The NSA debate has been maddeningly theoretical. So, here’s where I think everyone can agree with Snowden and why he is, in fact, a national hero. Americans cannot make a democratically informed decision without more information on the effectiveness of mass spying. As Snowden concludes, “it should be the result of public decision rather than closed conference.”

The more people examine classified evidence, the less they are convinced the NSA’s programs have been worthwhile. Large organizations, especially hierarchical ones like the federal government, as disturbingly susceptible to “group think“, where dissenters are actively shunned and groups converge on an idea that often ends up being stupid (i.e. the Bay of Pigs disaster).

The intelligence community needs a lot more critics, especially ones who are specifically tasked with protecting civil liberties. As I predicted, under any reasonable scenario of broader oversight, bulk collection of data, as we know it, will change. Since authorities will have to convince a lot more skeptics, the burden of proof will fall more on the NSA, and ultimately limit their reach.

If that happens, we can thank one person and one alone: Edward Snowden.

Read Snowden’s response in full, below and the rest of his live Q&A here.