The word ‘surveillance’ was first introduced into the English language around the turn of the nineteenth century, seemingly from the comités de surveillance that were formed in France from March 1793 to monitor the movements of foreigners and dissidents. With the ‘conspiracy her-meneutic’ of the French Revolution towering over the period, 1790s Britain provided fertile ground for the emergence of systematic state surveillance and its legal codifications, beginning with the 1794 Treason Trials and 1795 Pitt-Grenville Acts, and culminating in the Six Acts of 1819. The uncovering of the Cato Street Conspiracy to assassinate British cabinet ministers in February 1820 – largely in response to the Peterloo Massacre of 1819 and only two months after the Six Acts had been passed – further encouraged state surveillance of clandestine and radical societies into the 1820s. The presence of the Jamaican-born Afro-Caribbean William Davidson among the Cato Street con-spirators extended the threat from home-grown radicals to emigrants from Britain's overseas settlements, where slavery and its resistance had already resulted in the implementation of pioneering surveillance tech-nologies such as slave passes and biometric identificatory criteria.

Continued efforts to counteract radical uprisings through the use of counter-intelligence, intercepted letters and other forms of espionage raised ongoing questions about the limits of state intervention and the nature of governmentality. Jeremy Bentham's ‘Of Publicity’, published posthumously in 1843 but written in 1791, advocated open government, arguing that ‘secresy [sic] is an instrument of conspiracy; it ought not, therefore, to be the system of a regular government’. At the same time, Bentham argued in 1822 that transparency in the form of a free press, accessible institutions and what he called a ‘public opinion tribunal’ needed to be offset by the right to reputation and privacy. The seductively ambivalent practices of spying, peeping and prying were therefore increasingly understood as part of a potential dilemma that required careful balancing and evaluation: prying was both an ‘embodiment of the [public] spirit of inquiry’ and an unwarranted intrusion into private affairs. If, as David Vincent argues, the 1820s saw the emergence of a nascent self-regulating ‘liberal polity’, it was also a decade in which newly liberal subjects were still learning to ‘interrogate the conditions of their freedom’.