Sad but it happens. Instead of pointing fingers at random targets or looping into some conspiracy theories, and of course after reading analysis by waqas, I concludes that it might be an automated attack. Happened with phpBB too (who can forget that infamous automated hacking of forums around the globe). Maybe too much famous at Google's search made this forum a very likely target for automated bots.
At least that "useless material" (as mentioned by sah ) is now history (pretty much part of history other than few temporary caches). Something like vague memories of couple of days' older nightmare. "Somethings that should not have been forgotten... were lost. History became legend, legend became myth." -- Lords of The Ring
In my humble opinion, as KO admitted himself, that backups are must when running anything on internet. Moreover, it is very important to keep the pace with developers to keep your software updated and protected. Prevention is better than cure (especially when there is no cure). Already used 3 lives out of 9 lives
Hopefully, in this new "life-time", I shall try to avoid criticizing corporates and government
Cheer up, The show must go on. Or maybe as with United Kingdom's monarchy "The King is dead. Long live the King!"