When I first heard about the National Security Agency's PRISM operation at a conference in Washington, D.C., it wasn't clear just how significant that might be. I knew that the government was collecting information from emails, including the name and address of the recipients, the originator, the time and date of the message, and perhaps the size of the message. But it wasn't clear just how much the government could glean from that.

But that was before it became clear exactly how effectively visualization tools can show the relationships between and among points of data. I found out a few days later just how effective that can be when I was introduced to its use as a cyber-security tool. Now it turns out that the same type of illustration is available from MIT, and it uses your own email to produce the illustration.

As Brian Fung reports in National Journal, this is the information that Google has available from your Gmail account. If the government requests email data from Google, this is what the government gets. The tool, called Immersion, goes through your Gmail and reports to you on what it finds. Then Immersion displays it as a sort of bubble chart showing who you trade email with the most, and perhaps equally important, the relationship between those people.

If you look at the illustration at the top of this story, you'll see a cluster of colored bubbles. The size of those bubbles shows how much correspondence has happened between you and those people, effectively showing how important they may be in regards to you.

The illustration here is the chart of my Gmail account. The largest bubbles are public relations agents, except for the second-largest, which is my long-suffering Apple support person. Some of these bubbles also represent news sources, and if you could see them, there are thin lines between some of those bubbles showing that they also know each other. In this particular snapshot, I've left the names of those people out, but the same data is available with the names included.

If you click on the link in the word "Immersion" above, you can try this out for yourself. The results will appear in a few seconds, first with preliminary results, and then with more details as the data is analyzed further. For people who are not all that active on Gmail (me, for example) the amount that the data shows is sobering. Just imagine if Gmail is your primary means of email as it is for many people.

Now, for the really scary part. When Google handles your email, it gets this information, but it also has been searching for keywords within your email so that it can use it for advertising. What this means is Google not only knows all the information in your metadata, but also knows what is contained in your email. This could be a very revealing profile indeed. At least the NSA says it doesn't read the contents of your email. Google does, and it admits that it does. Which is more scary?