plagiarism thing going on at Penn: read here for the latest. Reading an article like this always makes me want to know the real inside story--it seems to me so infrequent that reporters can really get across the subtleties of a case. In this instance (though I have no first- or second-hand knowledge of the situation, meaning that I haven't looked at the books in question) it sounds completely persuasive that Elijah Anderson's work was cited without appropriate acknowledgment by another scholar, and that race played into the way the department then handled the plagiarism (or "undercitation," to use a more precise term) issue. (Anderson's classic book is A Place on the Corner, and though it's ages since I last looked at it, it's a pretty amazing work of scholarship.) But the subtleties of the personal and intellectual interactions, and the dynamic of a department, and the configurations of a discipline: this is the kind of thing that even the very best reporting will have a hard time sorting out into a coherent narrative.
UPDATE: Here's a longer piece by Anderson (who does not use the term plagiarism), including a detailed list of passages displaying unacknowledged overlap and repetition.