Rise of the idealistic nerd

President Obama said the surveillance programme was strictly monitored by lawmakers and a secret court

US President Barack Obama says he welcomes a debate about the right balance between privacy and security. That is good, because it will rage for a long while.

I suspect many in his administration are not quite so pleased about this public airing of secrets, but there is nothing now that can put the genie back in the bottle.

It is not only the raw debate that will grow. So will the argument about whether the people behind the leaks are heroes or villains.

It strikes me that the revelations made by ex-CIA employee Edward Snowden are of a piece with those of US soldier Bradley Manning when he gave a vast stash of US documents to the website Wikileaks.

Neither are leaks in the old sense - of a single, sensational story about a particularly scandalous operation.

Instead they are, at heart, about the breadth and depth of intelligence gathering and how the internet changes spying itself.

It is also about two young men who were horrified by what they saw going on and decided to expose it - in the words of my colleague, Paul Adams, "the rise of the idealistic nerd".

Edward Snowden said he "did not want to live in a society that does these sorts of things"

It is probable that as the technology changed, intelligence services had to hugely increase the number of fairly low-level experts they employ.

Possibly, their background checks were less rigorous than in the past. Maybe the type of person recruited was more committed to a technology that has gone hand in hand with a vaguely libertarian ethos than a commitment to national security, whatever the implications for privacy and freedom.

It is not certain how this will play for Mr Obama, but it does not look great.

It is true that it runs against the right's narrative: "Obama is weak on national security."

Once again, as with drones, he has shown himself to be rather ruthless with the niceties.

On the other hand, it plays right in to the hands of another conservative narrative: "President Obama expands the power of the state."

Given that it comes on top of the tax scandal at the Internal Revenue Service, and the raid on the Associated Press, it builds up a picture of an administration that plays fast and lose with civil liberties.

This resonates with the president's own natural supporters as well, and those on the left who feel "he is just as bad as former President George W Bush".

It adds to the general feeling of cynicism about politicians and suspicion of the power of the state.