The winning bid on the Charitybuzz auction offering a coffee with Apple CEO Tim Cook dropped from $605,000 to $600,000 earlier this week. Why? Because the bid had been placed using a stolen credit card.

The auction, which quickly became Charitybuzz's biggest ever auction, offers the highest bidder the chance to sit down for a coffee with Cook at Apple's headquarters in Cupertino.

It appears that one bidder was so desperate to spend an hour in Cook's company that he or she stole a credit card in order to place a bid of $605,000 on the auction.

Fortune's Philip Elmer-Dewitt asked a Charitybuzz spokesperson to explain why the top bid for the auction had fallen $5,000 between Friday evening and Monday morning, and the spokesperson confirmed that there was indeed credit card fraud involved.

The coffee with Cook auction is still ongoing, with 12 days left to bid. At present, a total of 84 people have placed bids on the auction, with the current highest bid standing at $600,000. The proceeds will be donated to The RFK Center for Justice and Human Rights.

The winning bidder will be allowed to take one friend with them to the coffee date, where they will both be subject to security screenings. They'll also be responsible for their own travel and accommodation.

A statement on the Charitybuzz website says Apple will be expecting: "Polite manners and respect for the generous donor [Cook]."

Although the bidders remain anonymous, Macrumors has suggested some possible identities of top contenders. These include Larry O'Connor, the founder and CEO of Other World Computing, as well as Rory O'Neil, Vice president of Product and Channel Marketing at Blackberry.

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