This is hidden brain.
I'm Shankar Vedantam.
Have you ever had one of those conversations where half the people in the room have a very strongly held opinion and the other half feel just as strongly in the opposite direction?
This happened to me a few years ago.
I was having dinner with friends in Washington, DC.
Everyone was talking about some shocking news that had just come out.
Tens of thousands of top secret documents from the National Security Agency, or NSA had been leaked to journalists.
Since at least 2008, the National Security Agency has been using secret technology to hack into secret and far reaching, and it's been going on for years.
The government can compel a phone company to provide this metadata, as it's called, for millions of customers.
The man who released all these documents was Edward Snowden, a computer security consultant at the NSA.
The documents detailed extensive secret us surveillance of people and governments across the globe.
Edward Snowden believed that what the NSA was doing was wrong and that the public had a right to know.
I don't want to live in a world where everything that I say, everything I do, everyone I talk to, every expression of creativity or love or friendship is recorded.
Fearing correctly that he was in the crosshairs of us security agencies, Edward Snowden fled the United States and found refuge in Russia.
Back at the dinner table with my friends that night, someone asked a simple Edward Snowden, hero or traitor?
One side of the dinner party was this man was a hero.
He had acted in the public interest, alerting Americans to heavy handed surveillance by their government.
The rest of the group, they were equally certain.
Edward Snowden was a traitor.
Who shares national security secrets that embarrass your country, endangers the lives of us intelligence agents and service members, and then finds refuge in Russia.