There is an exploit that allows cheaters to take over servers running Jedi Academy Mod 1.3-1.5 (I believe, my server running 1.4 was attacked) and use admin powers to give themselves empowerment and terminator, and abuse players with punish, slap, sleep, kick, etc. They do not need a password so changing passwords doesn't stop them.
There is a program that spots these cheaters and automatically kicks them. It is available here
I have had to ban over 40 IP addresses to keep these people out.
I have heard that the mod's author cHoSeN oNe is aware of the problem and is working on a fix.