Here are some general rules to live by. Do not give out your password to anybody. The account is meant for your use only. Failure to follow this policy will result in loss of computing privileges. Do not use programs that send passwords out as clear text.
Examples are, telnet , ftp , rlogin etc.
It does not matter if you are doing this on a machine other than one in our department. If you compromize the security of an account in some other machine or university, it compromizes our security as well. For, after all, we're only a few packets away on the internet. Besides, it is one of those things that can really irritate your colleagues. If you need to protect things, create a subdirectory and protect that.