A popular tool used to track eBay auction activity has shown some extreme deviations since the end of February, and some are speculating that the cause is due to account-hijacking or hackers. The unusual listing behavior comes at a time when eBay is fighting "Vladuz," a Romanian that eBay says is a known criminal.

The Medved Auction Count chart for the month of February show auctions fluctuating between 12,000,000 and 14,000,000 listings. Mike Medved, who publishes the charts, said he had no idea what was causing the eBay listing swings. "The program just looks at numbers that show up on eBay's web pages, and they are the ones that swing like this - and this is not one page, it is 30 different pages too" (http://www.medved.net/cgi-bin/cal.exe?EIND).

Bloggers who follow eBay have been commenting on the unusual behavior and have speculated that it is caused by a cycle of fraudsters listing many auctions under hijacked seller accounts, and eBay taking them down. eWeek wrote about the phenomenon last week (http://digbig.com/4rtxt), and Ed Koon, who publishes a website critical of eBay's response to online fraud, believes the listing fluctuations are due to hacking (http://www.ebaymotorssucks.com/scams030507.htm).

eBay spokesperson Nichola Sharpe said there are "a couple of issues" with the assumption that the swings in listings numbers tracked by MedVed are related to fraudulent activity. She said there are a lot of variables that come into play that could impact the MedVed data - from batch processes to how rolling out code to the site might impact and interact with MedVed results. "Our team looked at the data and there just isn't enough information there to tie the swings in listings that they show to any one cause. Also, it's important to keep the scope of our site in mind. We have approximately 100 million items listed at any given time and about 6 million new items get listed each day."

Sharpe said eBay knows exactly how many listings are pulled related to account-takeover activity. "I can assure you that the magnitude of the swings displayed in the MedVed data far exceed our real activity in this area."

Mike Medved, who publishes the auction charts, does not believe the swings are tied to fraudulent listings, nor does he think eBay's response fully explains the recent swings in his charts. His personal opinion, he said, is that some counting machinery on the backend of eBay may be screwed up and reporting wrong numbers.

eBay does not publish up-to-date listing data like that shown on the Medved charts. He said, "I wish eBay would make it easier and just publish the correct total somewhere."