I think a few people are jumping to the
misconclusion that some of the scammed bidders
were really shill bidders.  Most of the scammed
bidders have good standing accounts, most likely
not shill bidders.  Further more, when a bid is
retracted, yes, the bidder does leave a message. 
However, when the _seller_ cancels bids, it is the
_seller_ who leaves a message explaining why. 
Retractions and cancelations are listed together,
but they are distinguished from each other in the
list.  It is not uncommon for a seller to remove
all the bids at once when he wants to end an
auction prematurely and not sell to anyone.  The
seller's reason isn't going to change for each
bidder, so the reasons would all be the same. 
Thus, the reason why all of these bidders have the
same message and were done within a few minutes of
each other is because the seller did them to end
the auction and left them all the same explanatory
message.  Perhaps the bidding was not going high
enough for him to risk mail fraud.  I don't know,
hopefully if we see him again, he'll be easy to
spot.

Keys