The latest webmaster help video from Google's Distinguished Engineer Matt Cutts deals with auto-generated content and whether manual action is taken against these types of sites (i.e., whether the site will receive a Google penalty).
Many years ago, these websites were often referred to as "Made for AdSense" or "MFA" sites. The only reason these MFA sites were created was in the hopes that people would land on the page, not find what they're looking for, and click an AdSense ad to leave the page rather than hitting the back button.
Most of these types of sites are automatically generated with a script that takes snippets of either search results or web pages with those keywords on it. There is no real content to them, just the auto-generated snippets.
One user who has seen these types of sites asked Cutts specifically if Google is taking any action against these sites.
What does Google do against sites that have a script that automatically picks up the search query and makes a page about it? Ex: you Google [risks of drinking caffeine], end up at a page: "we have no articles for DRINKING CAFFEINE" with lots of ads.
"We are absolutely willing to take action against those sites," Cutts said. "So we have rules in our guidelines about auto-generated pages that have very little value and I have put out in the past specific calls for sites where you search for product a VCR or laptop or whatever and you think you really get a review and the new land there and the very first thing you see is '0 Reviews Found for [blah blah blah]'."
From Google's perspective, if a searcher lands on one of these pages and doesn't find what they are looking for, that results in a bad user experience, which is why Google would take action against these zero value sites.
Cutts also said that webmasters of sites with search results should make sure that those search results snippets aren't being indexed unless there's something highly unusual about it, such as data no one else has. But in this case, you still need to ensure that you aren't allowing Google to index search result pages that are saying "0 Results Found" because that isn't helpful to Google searchers.
Bottom line: if you're creating web pages of auto-generated text and snippets, you should be aware that Google can and will penalize your site. And if you're just a user who is finding these types of pages in the Google search results, you can send in a spam report.