Where did you get that? It simply means.."what(the hell or fuxk) are you?" or "who(the hell or fuxk) do you think you are?" for example, "니가 뭔데" what are you? "니까 짓게 뭔데" what the hell are you? As you see it, "니까짓게 뭔데" is more strong than "니가 뭔데" and "먼데" is often used in casual conversations instead of "뭔데".

ㅎㅎㅎㅎ Is that a typo or a Freudian slip? =P Mostly MBC and SBS. I watch YTN or MBN news.

couch*.. ouch

What do you switch on when you're lazing on the coach?

Yes, KBS is a public broadcaster of South Korea so it tends to be straight-laced. I don't care either way though, because I don't watch any KBS shows or news.