Out of the top 110 threads in the hikky board, only 3 threads were created by residents there (showin in the pictures below, with green boxes), one thread is a commercial thread by 2ch and the rest 106 threads were created by trolls.
Threads No. 1 - 55
http://i.imgur.com/YbAXY0d.png
Threads No. 56 - 110
http://i.imgur.com/JtOQhmU.png
The attackers are using bot programs to make their meaningless threads afloat and to prevent the board from working.
They are also mounting similar attacks on other boards in 2ch.