Microsoft Eliminates Use of 'Supercookies'

Responding to research from Standard University showing that Microsoft (among many) was using "supercookies" which re-enable themselves after deletion, the company has announced that they are eliminating such cookies.

In explaining the company's move, Mike Hintze, Microsoft's Associate General Counsel for Regulatory Affairs, said that the code was used only in older code that had been scheduled to be removed. Removing it now just accelerated the process. Hintze and Jonathan Mayer of Stanford both talk about working together on the problem.

There are many techniques to make cookies more persistent than they are supposed to be. Microsoft's appears to rely on cookie code remaining in the browser's cache even if the cookie itself is removed. The user would also have to clear the cache to make sure the cookie didn't reappear.