I believe this is for some people will be like a mini heart attack, for a moment, the blog that has been spent so much time, disappear.
Well, that was what I felt when that happened to me. Thinking "Wth login my blog and delete it", "where has I been login and simply forgot to log out?" to myself.
Then I found an option where it was never there before, the "Locked blogs" and my blog was inside it. Duhhh "what has I done this time ? Is google trying to terminate my Google Adsense by locking my blog ?"
Tried to find a way how to unlock it back, and saw a "Request Unlock Review" option, clicked on it, and it showed a notice that my blog has a malware in it, and a link redirect to the Google Webmaster Tools.
In Google Webmaster Tools, under the "Crawl" tab, clicked on the "Security Issues" and it showed me what was wrong with my blog.
And it was this javascrip script that I used to show my sitemap on a post
Removed it, and wait for the Google's employee to give my blog a review.
Glad that Google informed me about this malware. Who wants to surf on a website that has malware right ?