http://haacked.com/archive/2008/11/20/anatomy-of-a-subtle-json-vulnerability.aspx
tornadoweb/tornado#1009 (comment)
https://docs.angularjs.org/api/ng/service/$http

Long story short, due to a JSON security vulnerability, sites can output their json in the form of

{"d": ["Philha", "my-confession-to-crimes", 7423.42]}

Which represents the original json value of

["Philha", "my-confession-to-crimes", 7423.42]

Alternately (and my webserver does this), it can prelude the original JSON with the following string

)]}',\n

So the previous example would look like

)]}',
["Philha", "my-confession-to-crimes", 7423.42]

The require.js JSON plugin should account for this, currently it fails parsing with the following error message

SyntaxError: JSON Parse error: Unexpected token ')'

(when using the prelude version)