Correction. No, you can not. I found the password and tried to be the Lone Ranger. Ebay would not allow me to message them. Ebay sure has changed and is really giving the crooks all the advantage.
I miss the old days when everything was out in the open. You could loose an alt for making contact while the auction was still going but not as often if the auction had already ended. In those days you could mess with the bad guys auctions a bit. The bad part was that lots of the good guys auctions got messed with as well. The rules sure have changed over the years.