Why should I use gksudo for Gtk apps instead of sudo? [duplicate]

I read somewhere that people should use gksudo for applications that use the Gtk GUI instead of sudo? What's the reasoning for this?

Solution 1:

Source.

There are other times, though, when side effects can be as mild as Firefox extensions not sticking or as extreme as as not being able to log in any more because the permissions on your .ICEauthority changed.

These errors occur because sometimes when sudo launches an application, it launches with root privileges but uses the user's configuration file.

For example, if you launch Firefox with the command

 gksudo firefox

it uses root's Firefox configuration file.

But if you launch Firefox with the command

 sudo firefox

it runs with root privileges but uses the user's configuration file.