Incidents like the Snowden affair put my former colleagues in the intelligence community in an impossible position. Yes, the official explanations about the virtues of data-collection efforts can sound self-justifying and vague. But they’re still right. I know firsthand that Gen. Keith Alexander, the NSA director, is telling the truth when he talks about plots that have been preempted and attacks that have been foiled because of intelligence his agency collected. I know because I was on the inside, I have long held security clearances, and I participated in many of the activities he describes…

Let me break this to you gently. The government is not interested in your conversations with your aunt, unless, of course, she is a key terrorist leader. More than 100 billion emails were sent every day last year — 100 billion, every day. In that vast mass of data lurk a few bits that are of urgent interest and vast terabytes of tedium that are not. Unfortunately, the metadata (the phone numbers, length of contact, and so forth, but not the content of the conversations) that sketch the contours of a call to your family member may fall into the same enormous bucket of information that includes information on the next terrorist threat. As Jeremy Bash, the former chief of staff of the CIA, memorably put it, “If you’re looking for a needle in the haystack, you need a haystack.”

Unfortunately, during the Snowden affair, many news outlets have spent more time examining ways the government could abuse the information it has access to while giving scant mention to the lengths to which the intelligence community goes to protect privacy. We have spent enormous amounts of time and effort figuring out how to disaggregate the important specks from the overwhelming bulk of irrelevant data.

This is done under tight and well-thought-out strictures.