In my opinion it is a bipolar thing.

I never thought it was cameras - although I feel watched all the time. For me, the early religious teachings taught me it was "the big judge".
I think I would prefer cameras. (joke). I also tend to worry about the 'listeners' (The FBI who I am scared watch me because I twitter and make comments on politics and I am afraid they might consider me some threat) (NOW THATS BIPOLAR) lol
But, while I call it a bipolar thing, I actually think its just my brain making up reasons it can fathom to why I am experiencing an emotion. Like - if we couldn't disassemble an emotion - you would just feel 'watched' but not wonder why.
So I think the feeling of watched might be bipolar, and the creation of a reason might just be the mind. IDK, that's my best guess.
Best of luck to us all.
PS: at this time you feel 'persnickety' - great word, isn't it?