I have been using surveillance cameras and other monitoring systems in my work for many years. Any interactive system requires some level of surveillance. Agreeing to be surveyed is the entrance fee for any number of emerging interactive and personalized services. Surveillance is a very tricky issue.
Surveillance clearly constitutes some sort of invasion of privacy.
On the other hand, many people are comforted by the thought that there is someone watching over them on city streets at night. Surveillance system becomes protective witness. There is much research being done in Britain to automate the analyses of these surveillance images to detect suspicious activities algorithmically so that law-enforcement agents can get to the scene before anything happens. This requires the creation of an arbitrary definition of what constitutes suspicious activities. The current fascination with reality TV shows is entirely based on our deep pleasure in watching others, in getting that seemingly illicit peek into the lives of people we don't know.