[bayareaguy]

I would think that this should be obvious, but sharing your password in such a circumstance appears prohibited by the Facebook terms of service[1]. More specifically:

  You will not share your password, (or in the case of developers, 
  your secret key), let anyone else access your account, or do anything 
  else that might jeopardize the security of your account.

1- http://www.facebook.com/terms.php?_fb_noscript=1

[bugsy]

And there is a fantastic answer to such a question: "As a responsible worker, I take my contractual obligations seriously. The Facebook terms of service which I agreed to legally prohibit me from giving that information to anyone. I [have the terms here|can get them for you] if you would like to read them." If they reply, "Well we want it anyway." then the next reply is "I don't understand why you are asking me to break a contract. That is unethical. Do you routinely ask employees here to perform unethical or illegal acts?"