Back in 2012, Syria had a nation wide internet black out for two days. Local government officials claimed it was a result of some kind of terrorist attack, but according to Edward Snowden, US agents accidentally took the country's internet out.
In a wide ranging report on the former NSA agent, Wired says that Snowden knows the actual truth. Apparently a group of NSA agents were ordered to install malware on a central server in Syria which would allow the agency to keep tabs on just about all the internet traffic in the country. Unfortunately for the NSA, things didn't go as planned. Snowden says that while attempting to inject the malicious tracking software, the hacker unit accidentally shut the entire system down, leaving an entire country with no connection for 48 hours.
Snowden says the NSA apparently attempted to reverse its mistake, but were unsuccessful. At the time, the public was lead to believe local rebels ("terrorists") or even the Syrian government was responsible for the take down, but in actual fact it was the mistake of an elite US government hacker unit, according to Snowden. One thing to keep in mind is that Syria has experienced several blackouts like this since 2012, so it is likely that there are other third parties tampering with the country's web access.
Even though Snowden's cache of internal data has all been outed at this point, new revelations are continuing to surface. And now, the intelligence community has admitted to a second major insider leaking top secret data.