Iran monitoring all internet activity in the country

People have asked why Iran hasn't simply shut off the internet in their country. Well, it turns out they are analyzing all the internet activity using something called "deep packet inspection."

From the Wall Street Journal:

Deep packet inspection involves inserting equipment into a flow of online data, from emails and Internet phone calls to images and messages on social-networking sites such as Facebook and Twitter. Every digitized packet of online data is deconstructed, examined for keywords and reconstructed within milliseconds. In Iran's case, this is done for the entire country at a single choke point, according to networking engineers familiar with the country's system. It couldn't be determined whether the equipment from Nokia Siemens Networks is used specifically for deep packet inspection.

All eyes have been on the Internet amid the crisis in Iran, and government attempts to crack down on information. The infiltration of Iranian online traffic could explain why the government has allowed the Internet to continue to function -- and also why it has been running at such slow speeds in the days since the results of the presidential vote spurred unrest.

This probably means that changing your Twitter location to "Tehran, Iran" does about as much as turning your avatar green.