On Friday, Matt Cutts of Google tweeted that he wants users, searchers, webmasters and SEOs to report scraper sites via a special Google Doc Form.
Matt said:
Scrapers getting you down? Tell us about blog scrapers you see: http://goo.gl/S2hIh We need datapoints for testing.
As you may remember, before the Panda update, Google released an algorithm or filter that went after scraper sites. That has been out since late January, so I guess Google is seeking feedback on the quality of that algorithm and looking to improve on it.
It also shows that Google is not happy with the current state of scraper sites found in the index and they are likely going to do something about it in the next six months. So be prepared.
Forum discussion at WebmasterWorld and Google Webmaster Help.