Just from a couple of people I know who animate 
for Disney (I was asking them about job 
opportunities, and it usually comes out that I 
collect cels). Apparently, it's more of a problem 
on older cels (when they used to crop them and 
add different background), but Disney has gotten 
much better about authenticating.

On that note, I shall end this as I am not in the 
mood for arguing.

-Misha