I gotta say, this is really elegant. The Chinese government used a MITM to alter Baidu's analytics code into a web-based DDoS tool that's run by every computer that views one of the affected webpages (basically most Chinese web pages):
http://www.theregister.co.uk/2015/03/27/github_under_fire_from_weaponized_great_firewall/
The attack costs them nothing to run, normally you need to build a botnet or rally volunteers to do this sort of thing. And they used the Great Firewall to kill access to tools used to circumvent the Great Firewall's filtering even to places that aren't affected by the filtering (and blocking the attack practically means blocking ordinary Chinese users - just what they want), must seem like poetic justice to them.
Umm, what?
My computerese is a little rusty. 
Wow, my spell checker recognised computerese as a actual word. 
trucke
HalfDork
3/27/15 3:06 p.m.
I heard you can see the Great Firewall from space!
^Hahaha, actually I'm sure you can see it from space, but it would look like a bunch of warehouses with power and cooling buildings nearby.
In reply to Toyman01:
The Chinese government wrote a very prolific computer virus. It's sole purpose is to attack a popular american code repository service/website that hosts projects popular for circumventing Chinese internet censorship.
It's a piece of malicious code but it's not a computer virus - it doesn't spread and it goes away when you leave the affected webpage.
It doesn't even exploit any vulnerabilities, it just does a legitimate but pointless thing that becomes a bad thing when done by many computers at once.
In reply to GameboyRMH:
Right, I was going for shortest, simplest term explanation there.
Update: Turns out this system runs in the same data centers as the "Great Firewall" but is not technically part of it, and is being called the "Great Cannon"
https://citizenlab.org/2015/04/chinas-great-cannon/
And it seems to be a knockoff of a feature in NSA QUANTUM:
http://www.wired.com/2014/03/quantum/
