An ethics course is mostly about familiarizing you with several frameworks that can be used to make decisions about ethics.

For instance, "don't build stuff that can be abused" is not a good framework for ethical decision-making. "Abuse" has no clear definition, and "can be" is an incredibly high standard. By this standard, the hammer should have have been invented. It's incredibly easy to hurt someone with one! There are no safeguards whatsoever!