For years we blocked Baiduspider due to the fact their bots do not obey the robots.txt directive and can really hurt site performance when they unleash 100 bots on the site each pulling pages many times per second.
Last year, I unblocked Baiduspider's IP addresses, and now the problem is back.
I'm not a fan of blocking bots (or people) but I have noticed the site occasionally slows down dramatically because of Baiduspider.
So, unfortunately, I may need to block Baiduspider again.
My apologies to all the good people in China.