I think the bugtracker should hide email addresses for both the reporter and assignee. I don't like email harvesters and I think that email addresses should be hidden to non logged-in users (logged-in users can see member's addresses anyway of they go to their user-history page).
IMO the Directory package also shows email addresses by default and should be altered. OpenACS user's email harvesting has never been so easy as with this package. I have altered it on my own site.
Should I be filing suggestion bugs for these?