Thought comes to mind that when you’re watching everything, you’re watching nothing.
Camera’s are a toughie. They can be incredibly useful when for example some crazy thing happens like Boston, or a murder happens, or a store gets robbed, to quickly find the perp, or even keep an innocent person from being arrested. The problem is the government will always always take it too far, like the example of London, and use it as a income source, or worse. I think it can be good to have cameras if only they are used for investigative purposes. And I can see them for large events being used in live mode to look for muslims wandering around with backpacks...but there is a fine line that government always crosses.