Why does Google append while(1); in front of their JSON responses?
Source maps recommend a similar technique to mitigate against XSSI attacks by prepending ")]}" to your source map <a href="http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-xssi" rel="nofollow">http://www.html5rocks.com/en/tutorials/developertools/source...</a>