For the past couple of hours Google.com has been down in Shanghai. But not only that, also its adservers seem to have a serious problem: when opening a site with Google ads you get the error message that googlesyndication.com cannot be reached. Luckily Gmail still works, although it seems to be slower than usual.
Google.cn is working flawlessly, coincidence?
Update: (March 15, 8 AM) Google.com is working again in Shanghai, but all their adservers are still down. Maybe it was due to a misconfiguration of the Great Chinese Firewall? But why was only Google affected? And why not just Google.com, but also all the other country codes?