Q: Do you believe that data mining is necessary to keep the US safe? What occured in Boston was just the last of a series of attacks and I have read that American public opinion is divided right now between the ones who favour safety and those who defend privacy.

A: Some degree of data mining is inevitable for a modern state to protect itself, not only from terrorists, but also from crime, traffic and industrial accidents and catastrophic weather. The question is not whether we sacrifice our privacy for safety, but instead how much the government can see, what the limits are and how they are enforced. Right now, it seems as though the government reserves the right to define all those limits for itself. It asks us to trust its judgment. I think the limits will have to be spelled out, and the citizens will demand and deserve some sort of oversight over these operations, perhaps by a congressional committee (even though confidence in Congress is at all-time lows).

The other important point is what the data can be used for, and what conclusions can be drawn from it. Imagine, for example, that in their hunt for terrorists dataminers find possible evidence of tax fraud, or perhaps a ring of pedophiles. Can we expect them to turn a blind eye to it? I don't think so. In that case, what begins as an invasion of privacy to protect the nation turns into a surveillance state.

A: In my book, The Numerati, I argue that data mining is pervasive, in government and industry, and will only grow. Privacy advocates are sure to put up a fight, as will a number of government regulators. But the trends favor datamining. Consider what most consumers in the world are interested in. Most of them want convenience and economic savings, a cleaner environment, less waste, and more safety. Data mining promises results in all of these areas.

I should add that the data economy is full of hype, and that many of the promises turn out to be exaggerations, or false. In my book, I argue that the most problematic area is in data mining for terrorism. Companies like Amazon and Google, after all, can study the behavior of billions of shoppers, while anti-terrorism data miners have very little behavioral data about terrorists.   

Q:  International web users are also involved and I myself may be under surveillance after sending these emails to you…. Some people willingly publish personal data on social networks, others do not realize the dangers. What is your advice to internet users? Will people become warier when using the web after this datagate?

I think people will grow increasingly sophisticated about their data, and how to protect the secrets that matter to them. That said, it is remarkable how careless people are. A decade ago, hotels in the United States were among the biggest purveyors of pornography. Guests paid $10 or $20 to watch pornographic channels in their rooms. Who knows how many of them stopped to wonder, or to care, whether they were sharing their choices with the management of the hotel. That business has declined sharply, because travelers now bring laptops to their rooms, and look at Web sites. So now, their Web wanderings are available not only to the hotel, which runs the Wi-fi network, but also to a host of Web sites and their partners. These people may say in surveys that they care about privacy. And perhaps they do. But their appetites and desires lead them to share intimate details about their cravings with a broad range of companies and yes, the government.

My point is that while people claim to care about privacy, they often are not willing to forego convenience, pleasure, economic savings or the promise of security for it.