As protesters continue to clash with police in anti-government demonstrations, Egypt has pulled the plug on the Internet.
The cut-off happened just after midnight, local time, according to Internet monitoring firm Renesys, when the largest Internet Service Providers operating out of the country stopped providing the Border Gateway Protocol (BGP) routing information used to connect the rest of the world with computers in the Egypt.
HISTORY LESSON: Evolution of the Internet
MORE ON EGYPT: Twitter blocked in Egypt after unrest
Internet access isn't the only method of communications hit by the Egyptian government's blackout. It has ordered mobile phone operators to suspend service in some areas, according to Vodafone, which runs a network there. "Under Egyptian legislation, the authorities have the right to issue such an order and we are obliged to comply," the company said.
Egypt is experiencing its worst civil unrest in more than 30 years, as citizens have taken to the streets demanding an end to the government of President Hosni Mubarak.
Similar widespread outages have been blamed on cuts to undersea fiber-optic cables, but that doesn't seem to be what happened this time around, said Paul Ferguson, a researcher with security firm Trend Micro. An outage on a cable would not just effect Egypt, it would cut off all of sub-Saharan Africa." he said. "This is apparently a deliberate blackout."
"The Egyptian government appears to have ordered service providers to shut down all international connections to the Internet," Renesys said. "Critical European-Asian fiber-optic routes through Egypt appear to be unaffected for now. But every Egyptian provider, every business, bank, Internet cafe, website, school, embassy, and government office that relied on the big four Egyptian ISPs for their Internet connectivity is now cut off from the rest of the world."
Those four large providers -- Link Egypt, Vodafone/Raya, Telecom Egypt, and Etisalat Misr -- have dropped most of their Internet connectivity. Most Egyptian Web sites are now unreachable and people inside Egypt are largely unable to connect with the outside world using e-mail, instant messaging, or the Web.
But Egypt's Internet isolation is not complete. One service provider -- Noor Data Networks; the provider used by the Egyptian Stock Exchange -- is unaffected.
Twelve hours after the Internet shutdown began, the Egyptian Stock Exchange website was still accessible from outside the country.
On Twitter, a growing number of users, most of whom seem to be located outside of Egypt, are calling for users with a Wi-Fi router on Noor's ADSL or dial-up service to remove the password and share their Internet access with other users.
All told, about 88 percent of Egypt's networks have been cut off, according a blog entry on the Web site of network monitoring toolmaker, BGPmon.
Another network monitoring company Arbor Network, has posted a graphic illustrating the dramatic cut-off in traffic to and from Egypt.
Some countries routinely block access to specific Web sites, but this is the first time that a country has voluntarily severed its own Internet connection.(Also read: With wired Internet locked, Egypt looks to the sky.)
"This is a completely different situation from the modest Internet manipulation that took place in Tunisia, where specific routes were blocked, or Iran, where the Internet stayed up in a rate-limited form designed to make Internet connectivity painfully slow. The Egyptian government's actions tonight have essentially wiped their country from the global map," Renesys said.
Earlier in the week, the Egyptian government had reportedly blocked access to Facebook and Twitter, but with large protests expected Friday, it has apparently taken new steps to prevent people from communicating. " In this case the government seems to be taking a shotgun approach by ordering ISP's to stop routing all networks," BGPmon said.
Calls to major Egyptian ISPs and telecommunications rang unanswered on Friday, which is not a working day in the country and most of the Middle East.
"We are concerned that communication services, including the Internet, social media and even this tweet, are being blocked in Egypt," U.S. State Dept. Spokesman PJ Crowley said via Twitter late Thursday.