In 2008, three broken stairs were removed from the spiral staircase in the Fifth Avenue Apple retail store in New York. Former employee Mark Burstiner asked the Seele GmbH employees who were hauling them away if he could have one, and they said yes, according to Mark's story on Gizmodo. After storing it at his place for a while, he decided to put it up for auction on Ebay.
Shortly thereafter, Seele contacted Mark to claim ownership of the stair and demand that the auction be taken down and the stair returned to them. Mark removed the auction but refused to return the stair, claiming that it had become his property.
Now, the Ebay listing is back up. As of this writing, the bid is at US$9,9500. It's only a 3-day auction, so get your bid in early. Also be aware that the winner will take home a massive glass step (it weighs more than 200lbs) as well as Seele's ire -- they still claim ownership of the stair. Buyer beware, indeed.