Before revision: More reliable estimates put the total number of private and local government surveillance cameras in the whole of the United Kingdom at around 1.85 million in 2011.; History and purpose Introduction The " Ring of Steel " measures were introduced by Owen Kelly, then the City of London Police commissioner, following the Provisional IRA bombing campaign in London in the 1980s and early 1990s including attacks within the City such as the 1992 Baltic Exchange and 1993 Bishopsgate attacks.
After revision: More reliable estimates put the total number of private and local government surveillance cameras in the whole of the United Kingdom at around 1.85 million in 2011.; History and purpose Introduction The " ring of steel " measures were introduced by Owen Kelly, then the City of London Police commissioner, following the Provisional IRA bombing campaign in London in the 1980s and early 1990s including attacks within the City such as the 1992 Baltic Exchange and 1993 Bishopsgate attacks.