The Office of National Statistics make a priority of protecting the confidentiality of the data providers. Protecting confidentiality effectively is not only part of the legal terms under which the census data is collected but it is also thought to be closely related to ensuring high levels of participation. However, this comes at a cost in relation to the usefulness of the data. Certain researchers have argued that it is not clear how much actual public concern there is about the confidentiality of the census data particularly considering the non-sensitive content and that ensuring the effective usability of the data is as important in ensuing public confidence in the value of the census.
For a wide ranging discussion concerning the confidentiality issues in relation to Census data see Purdam, K, Mackey, E. and Elliot, M. (2003) "Personal Data and Privacy" in Isaias, P. (ed) E. Society, Lisbon, Portugal.
In the spring of 2003 the Office of National Statistics are consulting on a new protocol on Data Access and Confidentiality. See https://www.statistics.gov.uk/about/consultations/general_consultations/