We have more evidence of our past coverage that Google sends out notifications to Webmasters when they violate Google's terms of service. For example, Gabs received a notification and posted the details at Search Engine Roundtable Forums, explaining he was accidently hiding text on the page.
Here is the email he received:
Dear site owner or webmaster of *******co.uk,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: http://www.google.com/webmasters/guidelines.html In order to preserve the quality of our search engine, we have temporarily removed some webpages from our search results. Currently pages from *****.co.uk are scheduled to be removed for at least 30 days.
Specifically, we detected the following practices on your webpages:
* The following hidden text on ********.co.uk:
e.g. ********************** …
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 visit:
https://www.google.com/webmasters/sitemaps/reinclusion?hl=en
to learn more and request a reinclusion request.
Sincerely, Google Search Quality Team
Our past coverage of this includes:
- Google Sends Warnings to Sites
- Google Notification of Site Removal
- Google Steps Up Webmaster Spam Warning Emails
Forum discussion at Search Engine Roundtable Forums.

Comments:
SEO Loser
01/17/2007 06:32 am
Wow... I know this has been going on for a while, but reading the notification really makes you wonder. It makes sense for them to inform you of a ban or penalty, but telling webmasters to "correct or remove all pages that are outside our quality guidelines" makes Google sound like the omnipotent ruler of the web. I guess the wording just brushes me the wrong way. I'm glad they're sending these out and letting people know, the tone just seems a little overboard. Wait a second... I thought Matt Cutts DIDN'T want us building our sites for the search engines? If Google is able to identify the hidden text, why not simply ignore it?
SearcH EngineS WeB
01/17/2007 07:03 am
<blockquote>///we have temporarily removed some webpages from our search results</blockquote>This NEW reaction by Google is the results of the year-long, controversial comments made by SearchEnginesWeb on the blog of a very high profile Google Engineer. Before this tenacious insistance on just removing ONLY the offending pages - Google was removing EVERYTHING- for years Obviously, the Google Search Quality Engineers were studying the comments made - even though the later comments were DELETED - they were obviously being discussed at Google. To put these achievements into perspective, one has to realize the obnoxious comments that were made in response to these criticisms,and what eventually was achieved was something no one else at Google thought of or cared enough to advocate for.