Hello Linux Geeksters.
In this article I will show you how to disable the guest account login on Ubuntu 13.04 Raring Ringtail.
If you do not want strangers to login to your Ubuntu box, you should do this:
Switch to root:
$ sudo su
Append “allow-guest=false” at the end of the /etc/lightdm/lightdm.conf file:
# echo "allow-guest=false" >> /etc/lightdm/lightdm.conf
Optional: If you want to disable remote login, do this:
# echo "greeter-show-remote-login=false" >> /etc/lightdm/lightdm.conf
After the first reboot, you will have guest login and / or remote login disabled.