The paper offers an analysis of the problem of integrating ethical principles into the practice of software design. The approach is grounded on a review of the relevant literature from Computer Ethics and Professional Ethics. The paper is divided into four sections. The first section reviews some key questions that arise when the ethical impact of computational artefacts is analysed. The inner informational nature of such questions is used to argue in favour of the need for a specific branch of ethics called Information Ethics. Such ethics deal with a specific class of ethical problems and Informational Privacy is introduced as a paradigmatic example. The second section analyses the ethical nature of computational artefacts. This section highlights the fact that this nature is impossible to comprehend without first considering designers, users, and patients alongside the artefacts they create, use and are affected by. Some key ethical concepts are discussed, such as freedom, agency, control, autonomy and accountability. The third section illustrates how autonomous computational artefacts are rapidly changing the way in which computation is used an perceived. The description of the ethical challenges posed to software engineers by this shift in perspective closes the section. The fourth and last section of the paper is dedicated to a discussion of Professional Ethics for software engineers. After establishing the limits of the professional codes of practice, it is argued that ethical considerations are best embedded directly into software design practise. In this context, the Value Sensitive Design approach is considered and insight into how this is being integrated into current research in ethical design methodologies is given.