<<The URL of your profile alone can already give away your Gmail address. To hide this address from public view, you can switch your profile URL away from showing your name to using an address that features a 21-digit number instead of your username. However, as it turns out, this isn't a foolproof method either. By using a very simple trick, anybody can quickly figure out your Gmail address from these numbers.

Security blogger The Harmony Guy just told us about how this hack works. While the way to reveal these addresses isn't obvious, you can easily follow along and try this method out yourself.

How does it work?
First, you simply copy the numbers from a user's Google profile and then append these numbers to http://picasaweb.google.com/[numbers].

For some users who haven't customized their Picasa page, the username (which is also their Gmail address) will come right up.

How to Protect Yourself
In Picasa Web Albums, go to the settings page and add a new username. Then, select the new username for your gallery URL. As The Harmony Guy points out, you may also want to edit your nickname.>>

http://theharmonyguy.com/2010/02/12/using-google-buzz-can-expose-your-gmail-address/

http://www.readwriteweb.com/archives/hacking_google_profile_gmail_email_addresses.php

This is really not a good sign guys

It seems Google has disabled this... Now you get a page like this if you try to paste the profile numbers into the PicasaWeb URL: http://sorry.google.com/sorry/misc/?continue=http://picasaweb.google.com/101194710212904918574

BizAbh: Please don't take personally here what is important and what isn't. If people want to use features Google is providing to us they have a possibility to use them.

BizAbh, because exposing your Gmail address could open up more potential for Spam. What is "illigal" work?

Now instead of going to that "Sorry" page that I posted above: [http://blogoscoped.com/forum/167675.html#id167683], it goes to a "404 NOT_FOUND" page. So it looks like Google has indeed patched this bug.

Pretty cool site you've got here. Thanks the author for it. I like such themes and everything connected to this matter. I definitely want to read more soon.

Truly yours