Some sources have not ruled out Russian government involvement in the attacksn hitting Twitter and Facebook, which are thought to have been botnet-driven.
The BBC reported that, as well as Twitter and Facebook - other sites such as Google and Live Journal, the blogging portal, were also affected by the attacks, which dramatically slowed down internet access to the sites.
Cyxymu - real name Georgy - is reported by the BBC to have posted videos and blogs which criticise Russia over its conduct in the war over the South Ossetia region, which began one year ago on his blog, Twitter and Facebook accounts.
"It's a big surprise to me that my blog has meant that 250m people have not been able to enter Facebook," he told the BBC.
The blogger said he first noticed that things were not right when he realised his Live Journal page was not working.
"After, I entered Facebook to say Live Journal was not working and Facebook was down," he told BBC News.
"So I entered Twitter to say that Live Journal and Facebook were not working, and Twitter was down."
"And so I understood that it was under attack. It is not possible that these three services were all down at one time."
He told the BBC that he still did not have access to his blog or profile pages on any of the services. However, he said, he had set up a new blog to continue his writings.
Arbor Networks, meanwhile, said it was able to use its Internet Observatory to revealed that 55 ISPs in the Internet Observatory were exchanging roughly 200 Mbps with Twitter before the DDOS attack started.
Traffic then dropped to a low of 60 Mbps around 10:40am Eastern Time (3:40pm UK time) on Thursday and began climbing after that.
As of 6pm UK time Thursday, the internet monitoring company said that Twitter traffic was still down by 50% for the time of day at 150 Mbps.
From DNS, said Arbor, it looks like Twitter has moved some of their infrastructure to different address blocks as of 7pm UK time last Thursday.
Steve Gold, Infosecurity's technical editor, said that the effects on Twitter were more pronounced, as many users make use of overlay applications such as Tweetdeck to access their Twitter accounts.
"This means that if the Twitter servers take too long to respond to a software-driven comment, the overlay software times out and reports a problem, often suggesting the user tries again", he said.
"This only serves to make the problem worse, as Twitter's servers are still waiting to respond to the original data request, and then additional data interactions start stacking up", he added.
The net effect of this, he said, is that, whilst users of the Twitter site have been able to access the service with severe delays, users of overlay software like Tweetdeck have seen their service apparently frozen.
This, he went on to say, is what may be the reason for users reporting continuing difficulties in accessing Twitter over the weekend, even after the major effects of the DDOS attack have subsided.