My logs recently have been getting a lot of traffic from TurnItIn.com. They sell a plagarism detection service. Here is an example report from their system. Presumably they are scraping my site to populate their databases.
Interesting business, lots of nice aspects. First notice how they can sell their service to both the creators and the consumers of written works, i.e. they are middlemen. Nothing like a protection racket: sin, crime, fraud, paranoia, etc. Finally you have a great little network effect; only the most a paranoid customer is going to check for plagarism at more than one such site but you certainly are going to be drawn to the #1 site.
In time they could manage to become a standard; any work submitted to anyone might require an originality score from these folks. Maybe then can get some state legislators to make this a requirement for all the state schools. When all is said and done they can turn around and start collecting licencing fees for IP rights holders.
But, they better move fast. Lots of companies have a big pool of data they can use to check for plagarism: Google, Northlight, or even one of the big 80s online info services. They better move fast, get that brand advantage going.
Of course a system like this isn’t much help if your problem is with a journalists who’s just making it up. In fact it could be that what you want your writing to aspire the Goldilocks plagarism score. “Not too hot, not too cold.”