In the event of separation or divorce, it would probably be wise to password protect your account before you discuss the separation with your SO. Randy has some very interesting stories to tell about folks who forgot to do so.

If an account is not password protected, (which can be accomplished by calling the MP office) anyone with the right answers, can call UAL and get free tickets for, or upgrade, anyone.

A slippery sib could easily go in and wipe out a deceased parent's account without the other sibs even knowing. Sadly, I have seen some truly selfish behavior during the probate process, so something like that would not surprise me.