It appears that mozilla creates a subdirectory in the user's home
directory with the user's name, eg /home/fred/fred. I ran
<dpkg --purge mozilla> which according to my understanding of the
manpages should eliminate all traces of its existence - it didn't
say that exactly, but this seemed the most radical option.
However, the directories are still there, so:
Should I have done it another way?
Has mozilla left any other droppings on my system?
If there is no other way to clean up, shouldn't there be?