Google Privacy : Why is your gmail cookie still in the browser even though you close the browser

What is happening

1. Go to gmail.com
2. Give your userid/password
3. Close your browser

You will find that the you are signed out but your emailid is set as cookie.

Cookie details

• Name of the Cookie :: gmailchat
• Value in the cookie :: gmail accountname
• Cookie Type : Persistent cookie.
• Recommendation : Change it to Session Cookie.

HOW TO REPLICATE:

Updated Google Security on the issue and waiting to hear from them.