  Internet of Things (IoT) and cloud computing together give us the ability to
sense, collect, process, and analyse data so we can use them to better
understand behaviours, habits, preferences and life patterns of users and lead
them to consume resources more efficiently. In such knowledge discovery
activities, privacy becomes a significant challenge due to the extremely
personal nature of the knowledge that can be derived from the data and the
potential risks involved. Therefore, understanding the privacy expectations and
preferences of stakeholders is an important task in the IoT domain. In this
paper, we review how privacy knowledge has been modelled and used in the past
in different domains. Our goal is not only to analyse, compare and consolidate
past research work but also to appreciate their findings and discuss their
applicability towards the IoT. Finally, we discuss major research challenges
and opportunities.
