Recently, Google wrote one of those fact vs fiction posts, this time on the topic of "sites with auto-generated or otherwise unoriginal content." In short, Google said they do not allow sites with auto-generated or otherwise unoriginal content to participate in the AdSense program.
Fact: We don't allow sites with auto-generated or otherwise unoriginal content to participate in the AdSense program. This is to ensure that our users are benefiting from a unique online experience and that our advertisers are partnering with useful and relevant sites.
I spotted discussion around this post at DigitalPoint Forums where some publishers were shocked to hear this. One said, "I think content generated with article spinner softwares is also not allowed." Really, you think? Do you live under a rock?
But honestly, they have a reason not to know this. There are plenty of sites out there scraping and auto-generating content with AdSense on them. Google doesn't always do a great job preventing this from happening. Yes, it might be against their guidelines, but it still happens.
Forum discussion at DigitalPoint Forums.