groups and entering bugs

[Joseph Phillips]

Is there a way to make it so that when a user enter a new bug, and when
that user belongs to more than one group, that if he selects a
particular component for the project he is submitting the bug one, that
the act of selecting the particular component will force the bug to be
submitted as belonging to one particular group?

Currently, the user who belongs to more than one group must choose which
group with which he would like to submit the bug.  This is a problem,
because I can't rely on the user to make the correct choice.

Also, is there a way to prevent the user from entering the bug as a
public bug?  This can happen if the user does not choose any of the
groups when entering the bug.