What is the test for a reasonable expectation of privacy?

Claims to privacy must be balanced against other societal needs including effective law enforcement. Dickson J. (as he then was) in Hunter v. Southam Inc., 1984 CanLII 33 (SCC), [1984] 2 S.C.R. 145 framed a reasonable expectation of privacy as follows at pp. 159-160: The guarantee of security from unreasonable search and seizure only protects the reasonable expectation. This limitation on the right guaranteed by section 8 whether it is expressed negatively as freedom from “unreasonable” search and seizure, or positively as an entitlement to any “reasonable” expectation of privacy indicates that an assessment must be made as to whether in a particular situation the public’s interest in being left alone by government must give way to the government’s interest in intruding on the individual’s privacy in order to advance its goal notably those of law enforcement.