For IE? ...
Well, the 'hacker' story SOUNDS good - but that ain't the real reason for doing it - and we all know it. If the 'data' can be read by a program - the hackers easily get that info anyways.
The REAL reason for changing the names of the cookies is to prevent US - the USERS - from easily going through the pile of garbage in the 'cookies' folder - and delete the obvious tracking crap - such as anything with -ad- in its name. And finding cookies EASILY from other sites using 'file name' search - sites that we might not wish to have any record on our 'puters of having visited - like fu-obama.com - or other 'similar' names.
Almost ALL of the changes one sees that makes 'data' more opaque to the average user are done for EXACTLY that reason - to make everything an f'ing black box - to control the user - to keep the 'user' a dumb little advertizing and revenue raising target.
It is EXACTLY the same for the design of automobiles for the past 50 years (since the mid-60's) - make everything harder and harder for the shadetree mechanic to work on - so that more revenue is raised from 'authorized dealer' servicing.
And that folks - is the REAL wizard behind the gilded curtain.

Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good ...