
If you have accounts on more than one system on the same network, you
can allow yourself to log in from one to another by setting up
".rhosts" files.  This allows you to log in from one account to another
without having to enter a password.  This can also be an easy way for
someone to break into your account, if they can write their login to
your .rhosts file.  For this reason it usually best not to have one.

One last note on sharing accounts from the PUCC Policy Trifold, 
"Unauthorized Use of Accounts":

"Don't let any other person use your account."

