YP problems (was Re: Improving password security)

[Mark Fox]

>>So, we'll just re-invent YP, again!?!  No point doing something badly, when
>>you can get some other mindless jerk to do it _really_ badly.

All right already... Can someone please enlighten me as to why YP is
criticized so much? (If I misread the above flame, well, many others have
bashed YP in the past.) What is wrong with the protocol and/or implementation
and how would you correct the problems?
-- 
  Mark
  UUCP: ...harvard!m2c!applix!mark
  mark at applix.m2c.org