I can understand some buyers wanting to stay 
unknown when a valuable cel is bid on. As was 
mentioned in a previous post, there are a number 
of sour apples out there and a cel that is on 
many people's wish list could bring out the 
worst. 

On the other hand I also agree with Drac's point. 
There are many times that I do not bid on a cel 
because I recognize the bidder. Often I know that 
this other buyer is a bigger fan of a particular 
show/character than I am. (of course if said cel 
is on my wishlist...) 

So far none of them have been for cels I'm 
willing to fight over, so I have simply not bid. 
If the auction was for a wishlist cel I would be 
very uncomfortable bidding (due to possible 
shilling as stated before), but it probably would 
not stop me.