Later, you find out that one of the most aggressive bidders in the auction was actually just a buddy of the seller, trying to increase the price in his/her favor but avoid at all costs actually winning the auction.
You'd probably rightfully think this was unfair, and this is exactly what spoofers are doing in an electronic market. They are generating the illusion of interest to buy or sell, without the intention to actually do so, in order to move the market in their favor.