That electronic key cards store proprietary credit card data of guests is a story that seems to have more legs than a millipede.
Despite being debunked over the years as an urban legend, the story surfaces yet again on a UK based security website with the weight of credit reporting agency (and guardian of identity theft) Equifax behind it.
The article notes forewarns holidaymakers who "do not realise that hotel key cards can contain their name, part of their address and their credit card number" confirmed Neil Munroe, External Affairs Director, Equifax. "And, in the wrong hands, that could provide some really useful information to get an ID fraud scam going. If consumers' hand the cards back in to the hotel reception, or throw them away when checking out, they could make themselves particularly vulnerable to this unseen crime".
It is unclear where Mr. Munroe of Equifax got his information about hotel electronic key cards but people in the industry know that hotels use only one of three electronic tracks to store information pertaining to guest arrival and departure details.
The secure aspect of these cards were once explained by the delightfully named Mr. Hacker, deputy director of government affairs for the Ohio Hotel and Lodging Association who noted that "key cards usually have three tracks for potential information of which banks and credit card companies use two tracks, but hotel key cards only use one track".
He goes on to explain that "the software product that has been given to the hotel community actually prevents the use of the first two tracks on the magnetic strip, So the guests are not in fear at all of having any personal information on those cards whatsoever."
There are others (including this detailed article in smartertravel.com) who have countered the inaccurate technical information on this issue to no avail. Perhaps, someone with a name other than Hacker can come forth to put the matter

to rest?
Vijay is Chief Operating Officer and part-founder of Apple Core Hotels- a chain of 5 midtown Manhattan hotels offering value and comfort in the heart of the city.Member of the board of Directors - Hotel Association of New York.
www.vijaydandapani.com