Here are some of DFW's thoughts on plagiarism.
It was all pretty incredible. In many respects, this college was my introduction to the stark realities of class, economic stratification, and the very different financial realities that different sorts of Americans inhabited.
Some of these upper-class students were indeed spoiled, cretinous, and/or untroubled by questions of ethics. Others were under great family pressure and failing, for whatever reasons, to work up to what their parents considered their true grade potential. Some just didn't manage their time and responsibilities well, and found themselves up against the wall on an assignment. I'm sure you get the basic picture. Let's just say that, as a way of positioning myself to pay off some of my loans at an accelerated rate, I provided a certain service. This service was not cheap, but I was quite good at it, and careful. E.g., I always demanded a large enough sample of a client's prior writing to determine how he tended to think and sound, and I never made the mistake of delivering something that was unrealistically superior to someone's own previous work. You can probably also see why these sorts of exercises would be good apprentice training for someone interested in so-called ‘creative writing.'
… To anticipate a likely question, let me concede that the ethics here were gray at best. This is why I chose to be honest, just above, about not being impoverished or needing the extra income in order to eat anything. I was not desperate. I was, though, trying to accumulate some savings against what I anticipated to be debilitating post-grad debt. I am aware that this is not an excuse in the strict sense, but I do believe it serves as at least an explanation; and there were also other, more general factors and contexts that might be seen as mitigating. For one, the college itself turned out to have a lot of moral hypocrisy about it, e.g., congratulating itself on its diversity and the leftist piety of its politics while in reality going about the business of preparing elite kids to enter elite professions and make a great deal of money, thus increasing the pool of prosperous alumni donors.
…The basic view I held was that, whereas there may have been elements of my enterprise that might technically qualify as aiding or abetting a client's decision to violate the college's Code of Academic Honesty; that decision, as well as the practical and moral responsibility for it rested with the client. I was undertaking certain freelance writing assignments for pay; why certain students wanted certain papers of a certain length on certain topics, and why they chose to do them with them after delivery, were not my business.
Suffice it to say that this view was not shared by the college's Judicial Board in late 1984. Here the story gets complex and a bit lurid, and a SOP memoir would probably linger on the details and the rank unfairness of hypocrisies involved.
The paradox of plagiarism
The paradox of plagiarism is that it actually requires a lot of care and hard work to pull off successfully, since the original text's style, substance, and logical sequences have to be modified enough so that the plagiarism isn't totally, insultingly obvious to the professor who's grading it.
Update: D.T. Max questions whether David Foster Wallace ever did the stuff he says he did in the Pale King.
Practically speaking, one of the great struggles was to figure out what really happened or at least get close to it. David was writing his autobiography even as he was living it and the life and the narrative coincided but were not identical. Take an example. David used to tell people he sold thesis help for pot or money at Amherst. He even has his doppel do it in The Pale King and Stonecipher LaVache Beadsman, something of a stand-in for David, does it in The Broom of the System. David was one of the smartest people anyone ever met in their lives—everyone agrees on that—so it's obvious that in philosophy or English, and probably history or French or economics, all subjects he got A-pluses in—he could have done it. Anyone would have been smart to make that trade with him. But did it ever happen? His college roommate and confidante Mark Costello, the one who knew him best in those years, thinks not. He thinks it's David's self-mythologizing. I never found anyone on the receiving end of such a transaction or had direct knowledge of one, so it's not in the book. If I were writing a novel with David as the protagonist, it would certainly be something the character did. It's something he should have done if he didn't.
Still curious? Learn more about David Foster Wallace by reading Every Love Story Is a Ghost Story: A Life of David Foster Wallace . If you want to read some of his work, start with Consider the Lobster and work your way up to The Pale King, which was left unfinished at the time of his suicide, and Infinite Jest, his masterpiece. Finally top off with some wonderful cultural insights.