What's critical is who & why. I might follow you to find out where you go for a drink after work so that I can set up a brilliant surprise party for you there,

What's critical is who & why. I might follow you to find out where you go for a drink after work so that I can set up a brilliant surprise party for you there, on the other hand someone might follow me so that they can determine where best to murder them. A city might be filmed to support traffic efficiency and pollution control, if the footage then gets used to suppress political protest then it's a whole different thing.