I have been running my server for over a year now and spent a considerable time putting it together, while going through the logs i discovered that there have been countless attacks on it every single day am currently reading a lot of security material but it is amazing to see the number of evil people out there and what they can do. So if you have a machine connected to the net please make sure its secured and the first rule is if you can find your password in a dictionary even with a number or two at the end or beginning change it.
Have a secure day.