Yes, the number of .cn, .ru, .ua etc based ip's 'Viewing the board Chat, Offtopic & Diverse' got very noticeable, to the point of needing locking them out, now they'll waste their time and resource and getting an error message, and waste less server bandwidth here. I don't know why they fell in love with that particular board, maybe believing it would be less moderated than the main boards, thus giving a better survival chance to any spam post (if they ever got to post, which they don't anyway).
But am experimenting with better anti-chinese\russian measures at server level, if that turns out fine the board will eventually go back to normal guest view. Manageable here, but I can imagine the nightmare of running a very large forum, attracting 10.000's of spambots daily (here it's only around 1000 spam visits\day, exploding upwards if I lower some shields > example, take a look at the daily stats for 2013-03-15, 27.494 page views, normal is around 5.000...).