This would make the search engine spam free

There are basically 4 types of duplicat contents that are filtered out
1. Websites with Identical Pages
2. Distribution of Articles
3. E-Commerce Product Descriptions
4. Scraped Content

Read the whole story here
http://www.webconfs.com/duplicate-co...-article-1.php

And Naturally to avoid your pages content being copied use copyscape url codes into your blog.