mozilla/openwebapps — comment on commit 3d6948580cd7afff19f01fa574d4501c5fe45d36
File: addons/jetpack/lib/main.js line 356
By ianb:

_isLoggedIn is a bit fragile, because you can be logged out by something on the server (e.g., an expired token). It would be better to use SyncService.loggedIn() is better.