Yet the fact that she, too, was duped — and that the buyers would have been well advised to make their own inquiries — doesn’t mean she bears no moral burden here. She has let you all down. The seller’s greed may well have clouded her judgment, as it seems to have clouded the buyers’. Whatever the explanation, a morally responsible person will feel bad about what happened — even if she doesn’t think she did anything wrong.  The philosopher Bernard Williams dubbed this phenomenon “agent-regret.” His example was the way a truck driver should feel when he runs over a child who darts into the path of his vehicle. If the driver knew that he did everything he could to avoid what happened, he should still feel a special kind of regret about his involvement in the child’s death. It would be natural to want to seek forgiveness from the child’s family, for example, and maybe to contribute to the funeral expenses. An apology would be in order even if your seller friend was as deceived as the rest of you, and exercised a reasonable level of care.  So let’s focus on the idea of apology. You suggest that only one victim was seriously harmed, and that your seller friend has enough resources to assist the victim without jeopardizing her own welfare. Even if the seller has no obligation to make this victim “whole,” chipping in to help would make that apology a lot more heartfelt.  A final note. Selling fraudulent securities to your friends has to be rare, but something a little like this is pretty common in this country: You get involved in a pyramid marketing scheme (the outfit prefers the term “multilevel” marketing), and you sell all your friends sales kits. They’re your “downline.” You get a share of what they sell, too. People do this with high hopes that everyone will make money; when the reality turns out otherwise, it’s bound to lead to bad feelings. Most of the people who do this are acting in good faith. They’re usually just ignorant (and maybe a little greedy). Still, you might think the endless news stories about these schemes would make everyone’s ignorance a little culpable. Sellers should take care, and buyers should, yes, beware.  I have a friend who works at a firm that provides its female employees maternity leave. In advance of having her first child (and before using a six-week maternity-leave benefit), she fully expected to leave her job after her leave was over; she was clear about this in conversations with friends. Is there an ethical obligation for her to tell her employer? I understand that some people may fully intend to return to work and change their minds after becoming mothers. In those cases, it would seem fine to not return to work ever. However, is it fair to wait until after the leave is complete to notify an employer when there was never any intention of returning to desk shackles? Name Withheld  Maternity leave is a benefit of the job. While she has the job, she can take the benefit. No doubt there is a hope, perhaps even an expectation, that people will return from maternity leave, but if she hasn’t misled her employer, she isn’t at fault. (You don’t suggest that your friend has a habit of gaming workplace benefits.) Still, giving two weeks’ notice seems to be a usual norm in workplaces, and she’d do well to give her employer a little time to plan for her permanent departure. She’s entitled to the six-week provision all the same — and were the employer to try to deny her that benefit (say, by firing her), the employer would be at fault. Bear in mind that the employer could have decided to have a formal requirement of predeparture notice for all employees (whether on maternity leave or not), with a reward for compliance or whatever penalties for noncompliance are legally permitted. This might be prudent if many employees see their work in terms of “desk shackles.”  I have been a loyal Volkswagen customer for 30 years, having purchased seven new VWs during this time. I was disappointed by the news that VW rigged millions of its diesel vehicles to defeat mandatory emissions tests by detecting the tests and adjusting their settings so as to pass. The deceit continued with its marketing of “clean diesel” technology and its new C.E.O.’s declaring during an interview on NPR that VW “didn’t lie” — only to have to retract his statement later. Of course there are many who will suffer for a relative few’s wrongdoing. Please weigh in on this morass and help me decide if I can purchase a VW with a clear conscience. Name Withheld  I’d focus on the future here, not on the contagion of past wrongs. Volkswagen, it’s fair to assume, has learned that its “clean diesel” deceptions were bad business — maybe even just plain bad. High-level executives have been dismissed; VW’s market cap is less than half what it was last spring; it is facing fines and lawsuits that could amount to tens of billions. (The penalties were far, far less when Volvo, Mack and several other companies got caught cheating diesel-emissions tests in the 1990s.) It’s your favorite car, and as long as there continues to be reason to believe that the company is cleaning up its act — so that its new models don’t have any especially negative environmental impact — and you’re confident that VW will be around to support servicing when you need it, there’s no reason to switch. How you drive, not what you drive, may prove of greater moral weight.  Kwame Anthony Appiah teaches philosophy at N.Y.U. He is the author of ‘‘Cosmopolitanism’’ and ‘‘The Honor Code: How Moral Revolutions Happen.’’  To submit a query: Send an email to ethicist@nytimes.com; or send mail to The Ethicist, The New York Times Magazine, 620 Eighth Avenue, New York, N.Y. 10018. (Include a daytime phone number.)  Sign up for our newsletter to get the best of The New York Times Magazine delivered to your inbox every week.  A version of this article appears in print on April 3, 2016, on page MM20 of the Sunday Magazine with the headline: What Do You Owe the Friends You Unwittingly Scammed?. Today's Paper|Subscribe
The magazine’s Ethicist columnist on doing business with acquaintances, taking advantage of maternity leave and Volkswagen’s responsibility to its customers.