update readme

Author: dividuum

vncserver/README.md

@@ -5,6 +5,11 @@ This VNC server can be used to peek into a running
 info-beamer instance. Start the server on the raspberry pi
 and connect to it using any VNC viewer.
 
+Notice: You cannot remote control a Pi using this VNC Server.
+You can only see what's currently visible on the screen.
+If you need a full function VNC Server that supports
+input have a look at the link below.
+
 To compile, first install libvncserver-dev, then type make.
 
 ```