AdSense has been cracking down on the copied content issue - or so it seems. So why is copied content an issue?
From the AdSense Program Policies (which all publishers must adhere to) we have this excerpt:
AdSense publishers may not display Google ads on webpages with content protected by copyright law unless they have the necessary legal rights to display that content. Please see our DMCA policy for more information.
When you use someone else's work without giving that author credit for the work, that's considered plagiarism. Although you may not directly place your own copyright or name name on the work, omitting the credit for the original author is seen as taking credit for the work yourself.
Not only does this put you and your AdSense account at risk, it gives you no credibility at all in terms of knowledge or experience. If you have a blog full of articles about marketing, then you need to have marketing skills and experience to write about it. If you don't, and you are simply copying what someone else has written, how do you know the information you are providing to your readers is even correct? As an example, I have seen many blogs written by AdSense publishers - some of those have little experience with AdSense, or are new to AdSense and some of the "advice" they offer is not only wrong, it can get a publisher disabled.
Regardless of the foregoing, AdSense sets the rules for the type of content they want to see in a publishers blog. By that, I don't mean they'll tell you what you can write about - that's up to you, but they do get to choose based on content whether or not a publsiher even gets approval for an AdSense account.
AdSense expects it's publishers to work for their income - nobody gets money for nothing in today's world. They look for original work - whether it's articles, artwork, photos or other types of information, they want their publisher's to add something original to the internet, rather than just regurgitating someone else's work. They want your own unique thoughts and articles - and most likely, so will your readers and visitors appreciate a thoughtful article you've written yourself over some canned article from an article catalog.
One of the items in the AdSense Program Policies is a link to the Webmaster Guidelines - publishers must also adhere to these, and AdSense expects publishers to read them, and follow their suggestions.
An excerpt from those guidelines:
Scraped content: Some webmasters make use of content taken from other, more reputable sites on the assumption that increasing the volume of web pages with random, irrelevant content is a good long-term strategy. Purely scraped content, even from high-quality sources, may not provide any added value to your users without additional useful services or content provided by your site. It's worthwhile to take the time to create original content that sets your site apart. This will keep your visitors coming back and will provide useful search results.
This doesn't mean that you can't use an article, or a part of an article as a reference in your own written work (as I've done here by quoting the guidelines directly), it means you can't simply "scrape" the content from other sites and expect AdSense to accept that. Using a paragraph from someone else's article (with references & authorization) is an acceptable method of including content you'd like to highlight or discuss from other sites. Just don't make your entire blog from non-original work.
REJECTIONS FOR CONTENT
Besides the active publishers being disabled for copied content, we are seeing more and more rejections from AdSense for sites that appear to have no original work. For those of us who write original articles, we can only see this as a good thing. It means that AdSense is beginning to value originality...or more likely that the AdWords advertisers (they pay the bills, so they do have a say) are beginning to demand their ads not appear on sites will a lot of copied stuff.
But whatever the reason, AdSense is rejecting applications more frequently for sites whose contents are nothing more than articles copied from other sites. If you are having a problem getting an AdSense application accepted and you are submitting a site that you've filled up with work that you didn't create then you might try writing a blog full of your own articles, and submitting that instead.
AdSense Program Policies