This chapter considers the last possible interpretation of “reasonable expectations”, the two-tier model as originally also proposed in Katz v. United States. As is indicated by its name, the two-tier model consists of two separate, consecutive stages: adjudicators first ask whether the concerned individuals did in fact expect some form of privacy (the cognitive element) and then ask whether this expectation was reasonable (the normative model). The chapter exemplifies the model’s workings in existing case law and shows that its normative justifiability depends on the justifiability of its two components.