Hotmail punts user email addresses to advertisers

Yet another technical hitch

A glitch in the code at Hotmail has resulted in subscribers' email addresses being sent to online advertisers, the company conceded yesterday. This is not a problem unique to the Microsoft site, but it is the latest in a string of embarrassing technical problems for the free emailer.

The problem is this: when users open HTML newsletters containing banner ads, a phenomenon known as "data spill" occurs. In order for the company responsible for the banner ad to know where to send its data, opening the newsletter automatically sends the recipients email address and personal data back to the advertiser.

In a statement to The Register, Microsoft said that to the best of its knowledge no consumer email had been abused by this error. Microsoft was spared this further ignominy by the moral conduct of the advertising companies, however unlikely that may sound. DoubleClick, for example, automatically truncates personal information accompanying a referrer URL.

"Microsoft places the highest priority on consumer privacy and security," the red-faced company said. "As soon as we were made aware of the error the Hotmail team began work to fix it. It is a common problem on the net, and we expect to have it fixed by August."

Experts estimate that the site has had the problem for about six months, and that about one million addresses were compromised. ®

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