Threadwatch has keenly pointed out that it looks like Google is now sending out “You’re Banned for 30 Days” notices to sites that are deemed to have certain levels of quality content, but that violate aspects of Google’s guidelines. Via Search Engine Forums
Example slightly edited of specific names:
Subject: Removal from Google’s Index
Dear site owner or webmaster of [url removed],
While we were indexing your webpages, we detected that some of your pages were using techniques that were outside our quality guidelines, which can be found here: [link] In order to preserve the quality of our search engine, we have temporarily removed some webpages from our search results. Currently pages from [url removed] are scheduled to be removed for at least 30 days.
Specifically, we detected the following practices on your webpages:
We would prefer to have your pages in Google’s index. If you wish to be reincluded, please correct or remove all pages that are outside our quality guidelines. When you are ready, please submit a reinclusion request at [link]
You can select “I’m a webmaster inquiring about my website” and then “Why my site disappeared from the search results or dropped in ranking,” click Continue, and then make sure to type “Reinclusion Request” in the Subject: line of the resulting form.
Google Search Quality Team
And a post from Matt Cutts of Google on Threadwatch:
We all know Google likes to solve things “algorithmically” so how many “good” sites will get caught in this filter? At the same time, it’s promising that Google is now making an attempt to notify sites of any search spam screw ups. But notifying the web host in the CC? Is that necessary? Am curious what others think about this?