Artasi & Southperry - What Really Happened.

Nobody likes to be taunted, especially in public. And some people and companies don't enjoy a challenge, and would rather be spoonfed.
In other words: They feel that if you were serious about helping them with their security issue, you should have contacted Artasi in private and given him the technical details of the vulnerability, rather than humiliating him (and Nexon) in public, going "ha ha I can still get in, try again".

He has tried contacting them privately and was ignored, like all attempts to contact them.