Have people considered that there are two 
different types (possibly more) of fan-cles 
being made?  

One type is a fan making a cel of an image they 
would like to have or would like to practice etc 
etc and keep for them self to hand on the wall, 
weather it be an original work or a direct copy.

The second are fan-cel artists who see an image 
think that others will like that image so they 
take a copy of it paint up a cel and stick it up 
on auction as soon as possible with the intent 
of getting as much money out of it as they can.

Oh, I guess commissions would be a third 
category.  Commissions seem (in most cases) to 
be more like the first category, only by people 
who can make fan-cels (lack of skill/time/etc)

That second form of fan-cel artist is not a fan 
it’s a business.  An illegal one at that.
They don’t care about copy right holders.
They don’t care about other fans.
They only care about $$$.
Otherwise why would they be auctioning off the 
cel in the first place?

To answer the first question of what would I do 
if someone made a fan-cel of one of my cels?

Well if they only made it because they are a fan 
and wanted that image, I don’t know what I would 
do (or if I would even be able to find out).
But if they made the fan-cel with the intent of 
selling it to make a profit I would be really 
mad and would do everything I could to get their 
auction canceled and try to get their user ID 
banned.