I would agree that it is not a trivial black-or-white question about ethics for a number of reasons: 1. It wasn't Facebook who invented testing of products on d

I would agree that it is not a trivial black-or-white question about ethics for a number of reasons: 1. It wasn't Facebook who invented testing of products on different audiences. This was happening long before invention of computers. A cook altering the ingredients of the soup or a garment producer changing their supplier of fabric, they all altered the features of their product, sometimes genuinely believing that there will be more good than harm in it. 2. Customers may have right to know if something has changed in the product they love to make informed choices. With complex products like a digital platform or a car, it is no longer feasible to become aware of all the changes and it is absolutely impossible to understand them. Now it is a matter of trust of regulatory supervision more than "do you want to try our new recipe?" 3. Engineers may have a duty to build their systems responsibly and with respect to the needs and rights of the society. However expecting them to execute right judgement on complex legal matters is a big stretch, especially given the diversity of modern engineering teams and their cultural backgrounds. What is acceptable in USA, may be completely unacceptable in Germany or Pakistan and vice versa. Finding where to draw a line is important and it is not just (and mostly not) on engineers to do it. Engineers solve technical problems. This is a problem of trust and regulation, which must be considered by the whole society.