bkolobara I noticed that I can use any Gmail email address and it will be automatically activated. I guess this has something to do with the fact the google visits all links in emails you send to/from gmail for indexing.
I can't confirm this.
I used a secondary gmail account I own to sign up on my testbed site.
If this were to work, I assume Gmail would have already scanned my unread email and visited the link, no? But the account remains inactive, as you can see by the banner. (It also properly restricts me from posting, as you can see I cannot start a discussion).
Is there some other means by which I can activate the account, through this exploit you've discovered, without clicking on that link in the email? Do I just have to open the email? What?