What you do is either set up a dummy eBay account, or enlist one or more friends, then rack up lots of bids to simulate frenzied activity on the item you're trying to sell. Hopefully you or your cronies won't thereby win the item, but you can always relist it or offer it to a genuine underbidder. However, if you're a victim of it (it's not clear from your title), complain to eBay and have them investigate the bidding activity on the item in question; it is an illegal activity after all. Dave here (azda) is probably the expert on shilling, purely from an observer's point of view I hasten to add