By definition, Ethics is a branch of philosophy that involves systematizing, defending, and recommending concepts of right and wrong conduct. In computer science and security we do ethics whenever we take a decision that harms or protects the end user, taking for example, deciding to salt and encrypt the database so in case of a security breach most of the information remains safe for all of the people registered in our database.
Safety and security of the end user.
One of the goals of computer science and computer engineers is to make software for it to be used by an end user, in this case we as the architects of the software to be used by many have to take into account the safety of the people we are serving. This is one of the many reasons why testing is important and why a software without testing is unreliable.
Safety and greed.
Many of us have installed software from the appstore or the playstore and whenever we install this apps we are prompted with a security feature for us to agree in which kind of access we grant to the application we have installed. Some of use barely read what appears infront of us, but I warn you that this is very important, is a contract that the end user is agreeing to share its personal information with whoever is the developer of said app. As developers we cannot use the end user personal information as our asset, selling this information is important and protecting that is our duty.