I completely agree with Sol Orwell, particularly in this case, that plagiarism isn’t a “mistake” but a malicious act. And yet I have written before about the surreal cluelessness of some pseudo-plagiarists who actually don’t seem to get it. Maybe their mommas didn’t bring ‘em up right, and/or they were too damn dumb to work it out for themselves, but they seem to actually be under the impression that copying other people’s work is fine, all in a day’s “work,” or even that they are doing you a sort of promotional favour (the imitation-is-flattery school of plagiarism rationalization).
Fortunately, this kind of plagiarist is not much of a threat: they are too sloppy and lazy to ever make any headway in publishing. I’ve seen dozens of examples over the years of people who ripped off my work, and their websites have all been half-assed train wrecks.