http://raventools.com/blog/scraped-data-serp-tracker/ Google is trying to ace out SERP rank tracking by auditing anyone pulling in AdWords data. What does this mean? Basically if you want to comply with and use the Google AdWords API you can't be scraping the Google SERPs. SERP tracking is getting less accurate with personalized and "logged in" results, but it's still important for SEO's to know were they rank from a non-logged in view as a base mark, otherwise what do you have? Another blow to SEO IMO, maybe a win for all the SERP ranking tools popping up.