Personally, I  only do  this if  having the material  in question  in the
archive would  infringe on a  third party's intellectual  property rights
(eg pirated software) or if there  is enough such material to justify the
decision on technical grounds (ie  to save precious resources). Otherwise
I always tell people that I'm sorry,  but it's too late and people saw it
anyway, etc.

The problem is not really deleting the original message, you may not like
having to do  that but at least the request  is not morally questionable.
The problem begins when someone replies  to the "oops" and quotes part or
whole of the  original, and the victim then demands  that you remove that
other person's message as well (and all followup messages, for as long as
the  sun shall  rise,  etc), since  they all  contain  excerpts from  the
original text. You have  to draw the line somewhere, and  this is where I
draw it, because  I don't see by  what right you can demand  that a third
party's contribution  be deleted, especially  if it does not  just insult
your  heritage and  leave it  at that  but, as  is often  the case,  does
include  a meaningful,  if perhaps  a  bit heated,  discussion about  the
issues  raised  in the  "oops"  message.  Some  people will  settle  with
removing the quoted  text, but this makes the follow-up  message look out
of context  and often  it suggests that  the third party  is the  one who
started the  name-calling fest. Again, making  a third party look  bad to
protect  someone  who screwed  up  is  just  not  something that  I  find
legitimate. Someone will start asking for  a copy of the CENSORED message
and there  will be 200 "Me  too!" Plus of course  the oncoming discussion
about UNACCEPTABLE  CENSORSHIP on the list  and isn't it time  to start a
new list where freedom of speech is respected, etc.

  Eric