I worked for a big company where security was a big thing. I had to have an ID badge to enter the building. My boss once admitted to requesting the logs to determine if people on the team were really showing up on time to work. So I was aware the information could be used in let's say a predatory fashion for things not immediately obvious. However, I once had an ugly run in with another employee I did not know while…
You could make a lot of money in security if you were able to come up with a reliable way of tracking people via surveillance cameras, particularly in mapping persons movements and identifying when they aren't behaving as expected. Unfortunately this is exactly where it gets too easy to invade people's privacy. It is just a matter of time before we are able to do this, and we really need to have some way of limiting the invasion of privacy while still allowing for these systems to be used in positive ways.