airbnb/javascript — pull request #114 by paolocarrasco (2013-11-16 01:12:36+00:00)
Title: removing the attachment to the 'this' object of the private variables

Hey Harrison,
Don't you think that binding a private variable to the this object makes the variable/property public? Although the name makes it obscured, a new team member could access to these members and change them directly. It'd be better to deny that possibility.
http://javascript.crockford.com/private.html