Hi Pathik, Thank you for your question. I understand that when in private mode that Google still stores cookies.

Cookies are still required to login to an account when in private mode. 

However the login cookies are removed and not stored.https://support.mozilla.org/en-US/kb/private-browsing-browse-web-without-...

Please also consider using the Do Not Track feature https://support.mozilla.org/en-US/kb/how-do-i-turn-do-not-track-feature

Pathik said

How ro close the back door through which google can post its cookies also in the Private Mode.

The problem occurs when you in SECURETY have enabled block_dangerous_sites or block_web_forgeries. Firefox probably use Googles' list of suspicius sites.

@gnospen, it does.

You do not see cookies in the Cookie Manager while in PB mode, but cookies behave the same way in PB mode like in normal mode and exceptions are honored.

You would have to use JavaScript or a bookmarklet to inspect cookies in a private browsing mode tab.

You can open the Web Console (Firefox/Tools > Web Developer). Paste the JavaScript code in the command line and press the Enter key to run the code.

• unescape(document.cookie.split('; '));

cor-el said

You do not see cookies in the Cookie Manager while in PB mode, but cookies behave the same way in PB mode like in normal mode and exceptions are honored. You would have to use JavaScript or a bookmarklet to inspect cookies in a private browsing mode tab. You can open the Web Console (Firefox/Tools > Web Developer). Paste the JavaScript code in the command line and press the Enter key to run the code.

• unescape(document.cookie.split('; '));

What am I seeing? a cookie secretly loaded down to me that id me on this domain OR a cookie that is part of the pages i'm visiting and would have been loaded down to me if I had allowed it?