I'm trying to understand how OS X sandboxing works. In OS X Support Essentials 10.10 I could read this: ...in the Sandbox Data folder you will find only items specific to the application’s function or items the user has explicitly opened in the application. Items created and managed by the sandboxed application are the only original items in the container Data folder. Items that originated from other applications or a user’s file-opening action are represented as symbolic links that point to the original item outside of the container. I did some tests: I created a file with Textedit (File menu > open > new) to see if it showed up in the text edit sandbox, it didn't. What does the sandboxing do exactly?