Google announced their next spam target are those who are implementing manipulative browser history techniques to trick the user to thinking they are on Google's search results, when in reality, they are on a page of search ads.
How this works is when a user goes to a web site from Google's real search results, they then decide to click back to the Google search results. Now instead of the back button taking them to Google's search results, it detects the browser back button action and takes them to a page that looks similar to Google's search results but in reality are just ads.
Google said they will take action against sites and webmasters that do this.
To protect our users, we may take action on, including removal of, sites which violate our quality guidelines, including for inserting deceptive or manipulative pages into a user's browser history.
The deal is, a WebmasterWorld thread asks, do these webmasters who are implementing these tricks really care if their sites get banned? They are the type of build and burn sites all the time.
Forum discussion at WebmasterWorld.