I heard about a tool that helps publishers track their material across the internet. This would enable to publisher to know whether or not sites that download their material from other sites eg article directories will keep the links in the article. That is, any site that republishes the original work must keep the original backlink but they don't always do this. So anti-plagarism software would be able to locate those sites and inform the writer of the original content that someone is using his article without his/her permission or not providing the back link. I'd like to use that software, too. I know of one such site: http://beta.attributor.com Are there others? I'm looking mostly for open source and /or reliable freeware.
There are other free services like copyscape but who has the time, money, and resources to properly follow up with violators. Emails, letters, lawyers, phone calls, faxes, stress...Prevention is the best solution.
Even google have come with the statement that, there is no such penalty for duplicate content. they might rank those sites low but no penalty. so its all money and time wasting stuff. IMO.