Note from Little Sister

I logged on to check my email today, and noticed that there was a message from someone new, calling themselves Little Sister, here are the contents of the email:

You may not remember me, you may not trust me, but there are not many things I can say without setting off an alarm. It has come to our attention that there is a man contacting you. He goes by the name of Priest if I am correct. Whatever you do, you must not trust this man. He is with our enemy. We will be watching.
- Little Sister