Google, Akamai, and other web activity monitors have all confirmed that Syria has more or less disappeared from the internet. The country-wide blackout started at roughly 2:45 p.m. EST on Tuesday, and is still ongoing.
Government officials say they are working to restore connectivity, which, according to Reuters, is the worst communications outage for the country during its two-year civil war. The state-run Syrian Arab News Agency claims the blackout is the result of an optic cable malfunction. (The country connects to the internet via four gigantic cables, three of which are underwater.)
Security experts, however, say that a nationwide blackout due to a cable malfunction is unlikely, since all four would have to be cut simultaneously. More likely? Someone with access to the physical connections dropped the Border Gateway Protocol, or B.G.P., which routes incoming data, says The New York Times. "It's akin to someone removing all the street signs into Syria," said Matthew Prince, founder of CloudFlare.
Who would have done such a thing? Government officials blame anti-government rebels for the outage, while opposition forces say the cutoff is an "ominous" tactic employed by President Bashar al Assad's regime. Security experts have pointed out that disconnecting Syria from the internet makes it easier for the government to track insurgents, who will be forced to communicate using traceable two-way satellites.
Syria does have a history of internet shutdowns, with the last (much shorter) blackout occurring in December. According to the Washington Post, flicking off the internet in countries like Syria, Libya, or even Greenland is "almost trivial"; ask a few central facilities to power down and "you've (legally) disconnected the domestic internet from the global internet."
This can't happen in the United States. Whereas a country like Egypt has five major internet service providers, the United States has hundreds of independent ISPs that would all have to be convinced to power down simultaneously. PBS notes that Congress actually has considered an "internet kill switch" that could be employed by the government in the event of an all-out cyberwar. If the bill, first introduced in 2011, is ever signed into law, it would grant the president executive power to shut down the internet in an emergency. So far, the legislation has been met with fierce opposition.