Well... it really REALLY bothers me when a 
person I buy a cel from doesn't take it off of 
their gallery or sale site within a reasonable 
time.  Call it petty or territorial if you want 
but if I buy it, I don't like anyone else saying 
that they still have it!  >_<

When I first saw cel graveyards they perplexed 
me but now I don't mind them so much as long as 
they make it clear the cel is no longer theirs 
and say that I'm the person they sold the cel to.

That said, if I had a problem with the cels 
being shown online at all, I would have a 
problem with it.  I'm starting to have more and 
more reservations about online galleries with 
what seems to be a recent deluge of fancels on e-
Bay and other markets.

I don't think it would be rude at all to send 
them a polite message asking them to please 
remove the scan because, for personal reasons, 
you would rather it not be shown online.  It is 
your cel now, after all, and had you known 
keeping its image on the site was part of your 
bargain you would probably not have paid as much 
for it.