Other reports said that CCM is doing this on behalf of Eunjeung. I can't say if its a bright thing or not to get into a legal battle with mighty SBS right now (I suspect bias reporting coming T-ara's way) & the antis would probably eat this up and rage again..
But on the other hand... This may actually be bigger than just Eunjeung & T-ara. What she (or CCM) is doing is basically fighting for the rights of all entertainers in Korea. Five Fingers gave the middle finger to the trust actors gave producers when they dropped other projects to sign on a drama. This could & probably would happen to others also.
$125,000 is actually chump change for a law suit, it may even not cover the lawyer fees. But if Eunjeung wins she would basically give more protection and security for other actors in the future. If she lose, at least this will give this issue some public attention.
Whatever the result is she is a hero in my book.