The criminal courts have struggled to articulate an appropriate balance between privacy and police powers by protecting the individual's "reasonable expectation of privacy." This article serves to introduce all of the articles in this special issue using the Supreme Court of Canada case, R. v. Tessling as a jumping off point, to address the wider implications of the reasonable expectations test on the changing relationship between privacy and police powers of search and seizure. In upholding Mr. Tessling's conviction, the Supreme Court of Canada enunciated the test to be used to determine whether or not the police violated a defendant's reasonable expectation of privacy in the course of their investigation. A key question in this case was whether "the use of the forward-looking infrared (FLIR) device constituted an unreasonable search within the meaning of Section 8 of the Charter of Rights and Freedoms" thus violating the accused constitutional right to be protected against unreasonable search and seizure. The article discusses the subsequent journal articles which approach the issues from a variety of disciplinary perspectives and provide a context in which to examine the important ways in which new technologies are challenging the traditional balance between citizen autonomy and state surveillance. This article notes the technology and explains the ways in which design factors affect the technical possibility of private communications, point out that even though privacy is not an inherent characteristic of communication technology, and sometimes can even be an obstacle to its efficiency and reliability, privacy can nonetheless be imposed upon a particular communication through legal, social, or psychological means. References