It's funny that people use the term "Illegal". for these reasons.
Circumventing the operation of the software in any way is against the EULA that everyone clicks I accept in order to even open the wow client.
The MySQL overwrites valuses in the dbc on the fly aka. streaming the data. So in essance you are modifing the dbc files.
The extractor.exe you need to run so that your server has the dbc files to run must also unzip the MoPaq archive, and that is © blizzard.
Let's face is and not run away from the fact that we are all hacking and breaking the EULA.
With that said. Most of us feel that we bought the software so we should be able to develop things we like with it. Not for sale or any form of proffit mind you. but to experiment and learn.
Blizzard has never really cracked down too hard on any one that is not making a proffit off their work, as a matter of fact , most of the origional dev for mangos and others was leaked programming from blizzard and hackers who just wanted to see how it works.
If you are concerned with legality then I would suggest that the sysop and others actually write an MMO from scratch and dev that.
I can say this because I have many MUDS under my belt with origional code and other MUDS that I've assisted on like DiKuMUD and CircleMUD.
Anyway, thanks for the link and I allready have most of the dbc structures
Cheers!