As an engineer, your first duty is to protect the public, then your client, then your employer. You have that duty to the public regardless of whether you're being paid by a client or not, because it comes from practicing engineering, not from remuneration.
Idk why this keeps getting tied back to paid/unpaid. I can think of many a situation where someone gets paid, and also doesn't care at all to help.
i was responding to a comment about engineering ethics. engineering is a profession. engineering ethics is taught to student engineers in the context of a job, where you're getting paid. taking the (literal classroom) lessons out of context distorts them.
if you go back to your engineering ethics professors and say "gee, but what if i do this work for fun and just stick it up on a web page on the internet", they're going to look at you like you're insane, and then not know what to say.
> If I build something in real life
the last thing this thread needs is more analogies.
almost certainly in the framework of being employed or contracted to do engineering work. go back and ask your teachers what they felt they owe people asking them to design things unpaid, in their free time.