Would you believe that RCMP operatives used to spy on Tupperware parties? In the 1950s and '60s they did. They also monitored high school students, gays and lesbians, trade unionists, left-wing political groups, feminists, consumer's associations, Black activists, First Nations people, and Quebec sovereigntists. The establishment of a tenacious Canadian security state came as no accident. On the contrary, the highest levels of government and the police, along with non-governmental interests and institutions, were involved in a concerted campaign. The security state grouped ordinary Canadians into dozens of political stereotypes and labelled them as threats. Whose National Security?probes the security state's ideologies and hidden agendas, and sheds light on threats to democracy that persist to the present day. The contributors' varied approaches open up avenues for reconceptualizing the nature of spying.