When I was on my server, I was was disconnected randomly. It said: You logged in from another location. I dismissed it and thought that someone was just attempting to login to my minecraft account. The same thing happened again, and at the 4th time I was logged off for 5 minutes. I panicked and called a friend, and told him I was being hacked, I told him to come onto the server. He said that I wasn't on. When I logged back onto the server, spawn was in a mess. At first, I thought someone had kicked me from my server and had griefed the server. Then I was logged off again. My friend told me that I was destroying my own spawn, and that someone else was using my account. I quickly logged onto minecraft.net and changed my password, but I still couldn't log on. I looked at the server console and a guy called khobbits had joined (KHobbits is the creator of Essentials). KHobbits made himself Moderator and opped himself. When I tried to ban him he would somehow unban himself. When I banned his IP, he logged in with another account: khobbits1. From the console, I banned myself and told my friend to use some Groupmanager commands. He demoted KHobbits from moderator. KHobbits only disconnected after I banned his IP several times. After that I did a quick google search to see if the same thing had happened to anyone else, and other people were hacked as well. I'm not blacklisting KHobbits on this site, I think that it actually might not be him.