The title is a little misleading; the traffic wasn't directed to the building, but instead to two companies nominally registered there. Sophidea.com looks to be hosted at Hurricane Electric in Fremont, and DIT like it's at PSInet in Atlanta. The two companies appear to be related (a trace of sophidea.com goes through dynamic-internet-technology-inc.10gigabitethernet1-1.core1.fmt2.he.net).
I wish they had some numbers illustrating just how much traffic "most of China’s 500 million Internet users" would represent. I bet it would saturate a 10 gigabit line ;)