A major US internet company may have been knocked offline by hackers affiliated with the Russian government on Wednesday. Ustream the online video streaming service whose users has provided live coverage of events ranging from police brutality on Occupy Wall Street to the apparent mental breakdown of Charlie Sheen in 2011 was shut down for hours due to a major distributed denial of service attack focused on Russian citizen journalists in Moscow. In an exclusive interview with the Daily Beast, Brad Hunstable, the CEO of UStream, revealed that this was the third such attack on UStream in the past six months, a fact that the company had previously not disclosed. “It’s an attack on the freedom of the Internet” said Hunstable.

Ustream has become a highly popular way of chronicling the ongoing street protests against the Putin regime in Russia, which are not covered in the mostly state-controlled media. At one point, at a protest on December 6, 2011, over 500,000 people in Russia alone were watching one particular live stream of a protest. The website has been used to chronicle protests in other countries, including the Arab Spring protests of 2011 in Tunisia and Egypt.

The attack, which has kept the site offline for nine hours began at 2:30pm Moscow time (5:30AM EDT). It used 25,000 servers, based mostly in Russia, Kazakhstan and Iran to send the hugely popular streaming site, which has 55 million users a month and 10,000 live streams at any one time, offline. The previous attempts, which happened on November 6 and January 6 had a very similar footprint and also kept the site offline for about nine hours. These three attacks have been the only ones to ever keep Ustream from operating. Hunstable described them as “highly organized [and] so adaptive.” He noted there are “many ways to do denial of service, normally you only do one method. [This is] seven methods back to back to back to back, most adaptive denial of service that I’ve ever seen.”

A distributed denial of service attack (DDoS) operates by overloading a website’s serve with information requests, flooding it so that it cannot handle the influx of traffic for legitimate users to use. The attacks are often coordinated by a botnet, a web of compromised computers acting at the whim of the hackers behind the attack. These computers constantly attempt to access the site. This floods it with traffic and keeps it from functioning effectively.

This is not the first time Ustream has run into possible state censorship. The website is blocked in countries like Iran, China and Syria. Although Hunstable is loath to connect the attack with a particular government or organization, saying “I’m not going to speculate on who it is,” he is still indignant. Hunstable insists that “We believe in our mission, we believe in our vision in life and will aggressively bring livebroadcasting to anyone who wants to use it in the world.”

Despite the attacks, Ustream users inside Russia are still optimistic too. As one, Yazykov Pavel, told the Daily Beast, “our reporter Roma shoots great videos about the protests here that the whole world can watch on U-Stream. It is a bit down now but still works and Putin is ultimately [screwed].”