I'm sure it's the same cookie that downloads to your computer whenever you sign in. I guess we are just going to have to agree to disagree. I don't feel that it's that big of a deal. I don't understand why you guys even clear your cookies, it's not like they pose a security risk. If you are on a public computer and don't want your login info saved, then maybe that's understandable.
I have my computer and some of my family and friends use my computer, too. I have my browser set to delete all temp, and private data at closing! I also have all my passwords protected with Roboform. I guess it's being paranoid but I do love my privacy and security.