If it's the person I'm thinking of, they didn't take down best korea's internet, they DDOSed a couple of externally facing sites. Like not even anything a korean citizen would use, they just blocked foreigners from seeing press releases and tourism information.
Sort of, the real issue was it had no advertising of its own, just Randy Pitchford synergising buzzwordsalad on twitter and trying to create a rivalry with Overwatch. Nobody really knew what it was supposed to be from advertising, because nobody thought to just say "FPS MOBA".