For a recent project, I was discussing with @johnshew about the way JavaScript developers can embed private members into an object. My technique for this specific case is to use what I call “closure space”.
As you can see, closure space properties can be a great way to create really private data. You may have to deal with a small increase in memory consumption but from my point of view this is fairly reasonable (And at that price you can have a great performance improvement over using the regular way).
http://angularclouddataconnector.codeplex.com/