Internet watchers reckon that the DDoS merchants that hit Twitter et al were out to get a blogger named Cyxymu who writes about Georgian affairs. If in doubt, blame the Russians.
That theory doesn't add up, or at least not without more evidence to back it up.
If you wanted to stop a blogger is the best way to attack the world's number one Internet micro-blogging site (Twitter), its number one social networking site (Facebook) and its number one video sharing site (YouTube) thereby drawing even more attention to their presence? No attack against these entities was likely to succeed for more than a few hours, however badly defended people say twitter is.
There are plenty of people who want to stop individual bloggers from airing their views. But Twitter's presence in Russia is miniscule and far too small to bother right-wing Russian groups, who might want this individual silenced. These groups invariably have a parochial interest in stopping their fellow Russians from reading such material so it's unlikely that they would have done it to stop consumption by Westerners.
If anything a more plausible theory is that it was an agent provocateur looking to advertise the cause of Cyxymu.
Internet DDoS outages are fast becoming minor key conspiracy theories. Anyone can claim responsibility for them and anyone can be blamed for them. Theories on an e-postcard.