I'll just steal one of the comments from the article. "It isn't new, and it's just as overstated as previous studies. The 80% accurate identification rate applies only within the 5,000 subjects. The identification rate will plummet when the pool of writers expands to everyone who can write in English" Like I said, if you can narrow the pool to a small amount of people, than you probably could accomplish this (but even then, there's always the chance two people have similar writing styles.)