I agree with Vincent. I've gone trolling before when I was outbid on an item I looked at the winning bidders feedback score and what % he has dealt with that seller. If it is high then go into the sellers feedback and try and matchup feedback scores to find who won the item i was interested in. It doesn't always work and is time consuming but sometimes you can find out who won items. I have never contacted the bidder, just curious to see who's buying.
