Ionic Playground, $http, and CORS

I am trying to put together a Playground snippet to demonstrate the use of a Service and $http/$resource to access external data. The problem is that I am running into CORS constraints. For example, I am using the link to “echo.jsontest.com/conditions/frightful” that is in your tutorial. However, it breaks w/ an error in the console…

Origin http://play.ionic.io is not allowed by Access-Control-Allow-Origin.

I don’t control the service so I can’t change its headers. And, I can’t use your proxy workaround. Thoughts on how to address CORS issues in the Playground?