Simple example (DataTables package) works on JSFiddle but not locally

I'm trying to run a simple example using the DataTables package. For some reason, my code runs on JSFiddle, but does not work locally (the buttons to export to CSV, etc. do not work).

Why could this be?

Here's the JSFiddle in question: http://jsfiddle.net/9jf2k53p/

And the code can be found here: http://stackoverflow.com/questions/25597089/simple-example-datatables-package-works-on-jsfiddle-but-not-locally

Thanks very much for your help.