Nicholas Knight said:
No one, NO ONE, has said any sort of filtering
must take place by
default.
All these arguments about appeasing those who will attack us for not
filtering, are meaningless if a non-logged-in user approaching the site
for the first time will see the images that it is proposed should be
filtered on the grounds that most people may be upset to see them. So
what's the point of filtering if we only do it for people who are
motivated enough to either create a user and log in, or fill in a form
saying what kinds of image they want to have filtered?
If you'd read the pages on meta that Christaain has pointed to
repeatedly, you'd see there are already proposals to use a cookie-based
system and present anonymous users with a disclaimer page permitting to
make exactly that choice.