My advice is to forget about it. One of my articles has been scraped at least 50 times and many others at least 10 times. A small percentage gave a link back, but most didn't. But the rankings of my original pages haven't been hurt at all. In fact, I think that Google's algorithm may regard this as a positive signal, since it shows that other people think your article is worth copying. Anyway, I would rather spend my time working on new articles than to worry about scrapers. So I suggest that you just forget about it.