It works on servers where you can edit game files ( removed or hacked gameguard).
How to get accounts information from many players on server? Easy way.
You need: your own l2j server (easy) chronicle this same like server you will attack, modificated l2.ini file, and instal maker like icinst.exe.
Remember prevent ppl to connect to database, they cant get on char choose part.
Prepare l2.ini and change server ip on your own server ip. Make install program and name it like (wallhack for XXX server) this install file will install your prepared l2.ini not wallhack. Share your "wallhack" on speedy shere or wherever.
Now you have to join some clans and on forum write that you've just found great wallhack.
Many ppl will try it and they wont be able to login on their L2 server they will try to join yours :) When they will not be able to log in they will obtain no info. You just need to get passwords from login server best way is to log all info in text file. You have to a little change login server scripts. They wont be able to login so they usually use updater then and they will get acces to their server.
That's all if you will be able to distribute your "wallhack" to many forums and many clans of choosen server you will get a lot of account informations :) During 2-3 or more years of playing you will be able to close server if someone will make you nervous ;)
I can write more about l2j instalation and modification but you can find it everywere.