The government of Egypt ’s attempted crackdown on mass protests has been aided by an American firm that sells telecommunications software that allows the authoritarian regime to spy on citizens’ emails and cell phone communications.

Narus, located in Sunnyvale, California, sold the Egyptian government Deep Packet Inspection equipment, a content-filtering technology used to inspect, track and target content from users of the Internet and mobile phones.

According to a Narus executive, owners of the software can record everything that goes through the Internet in their country, allowing them to read emails and attachments, view browsing histories and even reconstruct phone calls made over VOIP (Voice Over Internet Protocol).

Founded in 1997 by Israeli security experts to create and sell mass surveillance systems for governments and large corporate clients, Narus is now owned by Boeing.

Egypt is not the first country to use Deep Packet Inspection equipment to spy on protestors. The government of Iran reportedly used similar technology sold to it by Siemens and Nokia to hunt down political opponents following the country’s national elections in 2009.

The Cairo government also has received help from the United Kingdom ’s Vodafone Group, which complied with a request to shut down its cell phone network during the uprising.

-Noel Brinkerhoff