No Place to Hide: Freedom and Identity

"These companies are, in essence, becoming private intelligence operations. They collect information, they analyze it, they find links among people, they look for tendencies, and they do it much faster than traditional intelligence services were ever able to do," said Harrow.

Lessons from 9/11

There certainly is an argument to be made for the government to engage in information-sharing.

Take the example of 9/11 hijackers Nawaf Alhazmi and Khalid Almihdhar. Even before the attacks, they were already on U.S. government watch lists because of possible links to the bombing of the USS Cole in Yemen in October 2000.

But federal agencies like the CIA and FBI failed to share their information with each other. They were not technologically nor bureaucratically equipped to do so, and they failed to connect the dots that might have led to the unveiling of the plot.

The CIA apparently didn't know Alhazmi and Almihdhar were already in the country when it alerted the Immigration and Naturalization Service, FBI and Coast Guard not to let them in the country. They were even booking flights using their own names, and did not trigger any alerts.

Private databases could have been useful because Almihdhar gave an address also used by Marwan Al-Shehhi and Mohamed Atta, two of the hijacker pilots. Again, no one connected the dots between someone on the terrorist watch list and his accomplices.

Atta made a plane reservation with a phone number that could have tied him to five more of hijackers. Alhazmi used the same address as another hijacker, Salem Alhazmi. And ironically, there was one more number shared between Almihdhar and another of the hijackers, Majed Moqed: a frequent-flier number.

However, Jeff Jonas, a computer scientist who has received financial backing from the CIA, points out even these precautions may not have stopped the tragedy.

"I fear that, maybe, if we knew they were going to get on the plane, we might have surveilled them on the other end, waiting for them to get off the plane, to see what meeting they were going to," he said. "In fact, they would have never landed."

Who Is Nicole Robinson?

Today, almost any piece of information in the public record is available to private companies who market that information to others. And the government, with only some limitations, is able to obtain it as well.