Open a window in private browsing mode from a Firefox add-on. Uses a deprecated interface. CMON, recommend a replacement please! https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIPrivateBrowsingService

gistfile1.txt

const {Cc,Ci} = require("chrome");
var pbs = Cc["@mozilla.org/privatebrowsing;1"].getService(Ci.nsIPrivateBrowsingService);
pbs.privateBrowsingEnabled = true;

var windows = require("sdk/windows").browserWindows;
windows.open("https://www.google.com");