I won't go into detail here, but myself and a few friends and contacts have all noticed the same thing - Google's US datacenter (or whichever one serves most of the US) is dropping pure whitehat sites out of the index for a few high competition terms. Sites that were ranking in the top 5 are disappearing from the SERPS, but are not banned. This is only showing up on 1 datacenter, and the surrounding sites are usually unaffected. Want proof? Check the tool I'm using: http://www.mcdar.net/dance/index.php What the heck is going on? This is NOT the google update we're accustomed to.
can you give more specific pls? i have some web sites and i did not noticed any similar problem. my web sites have index on us datacenters
White hat is defined differently by different parties, including Google. As I just mentioned in another thread, paid links are being cracked down on. So is reciprocal linking (which has been frowned upon for awhile). The times are changing - Google is trying to de-spam the index.
Fortunately for my sites, I haven't bought any links, nor have i done any exchanges or spamming links.