I recently purchased a domain and the corresponding website. For as far as I could tell, in the 12 months prior to my purchase, the site was well optimized within Google and had over 40 search terms on page 1 of Google in a really competitive space (lending-related).
When I made the purchase, the domain was transferred from seller's GoDaddy account and into my GoDaddy account and I placed privacy protection on the domain. We did not move the hosting of the site--I took over his hosting account. And I did not make any significant changes to the website.
About 1 week later, the site was totally removed from Google's index and I received notice in Google Webmaster Tools that the site may violate Google's quality guidelines. I filed reconsideration request telling Google that I was the new owner and that if there were any violations, they were caused by old owner. One week later, I got note back from Google saying they had received my reconsideration request and if they think issues are cured, then they will reindex the site. That was over a week ago and so seemingly they are not putting it back.
My question is this: Does Google somehow automatically know when domains change hands and does this cause them to manually review sites? The site in question was aggressively optimized but I don't understand what would have caused Google to take action on the site when they did. In other words, if they were going to take action, why wouldn't they have done it in the prior 12 months or does the domain transfer put the site into some queue that makes them review it?
BTW, the site in question has a SEOMoz domain authority grade of 85 and still is showing up as PR 5
Thanks very much for your time and consideration