What use does the == operator have for String?

In Java, if you want to compare Strings by value you need to use the String.equals method. This leads me to my question.

Why is the == operator not overridden to do the deep comparison ? Does it actually have any uses ? Why would one compare String references ?

Edit: I am not asking what the == operator does. I am not asking how to compare Strings in Java.

I am asking what uses does the == operator have for String in Java, if any at all.