I heard people say that swimsuits are just an illegal patch for private servers. Is this true?
They're illegal patches for both the real and private servers. (can be applied through very difficoult means to the first and very easily to the second) They were a great source of hacked accounts once, since NCSoft refused to see the difference between harmless graphical changes and things like zoom hacks, etc. Hence contributed to the popularity of the bad hacks (after all if you've gone and done the illegal thing anyway, you might as well take them all).