The Great Firewall of China can be used to "weaponize" any website passing through it. So, it can be used to inject a malicious script on Baidu delivered to non-Chinese IPs (as we see here) or Chinese IPs. It can also be used to inject a malicious script into Google AdSense for Chinese IPs as well as China has control of a digital certificate provider accepted by all major browsers and operating systems. One they have issued SSL certificates that can be used to impersonate Google et al this year.

The bottom line is that, much like the matrix, everything within China is still part of that system and can be weaponized by the Chinese government. So, be sure you never have anything from within Chinese IP address space loaded by your web pages or apps.