It's more difficult than you think. For one thing, the eBay bots look at the IP address as well as at the actual name.
If you think a seller is doing this, you can report her to eBay. There is a Report key on every listing.
Although names are now masked, you can compare feedback numbers in considering whether there is "shilling" going on.
Most important, the shill bidder does not want to win. If you are being outbid, even if it seems you are being outbid by the same bidder every time, there is probably no shilling going on. You are just being too conservative in your valuations. Or the other guy is too enthusiastic.
If you are being outbid, and the high bidder then consistently cancels his bid and does not re-bid, there is a chance of shilling.
Give us an auction number and we will cast a cold and fishy eye on it.
