How small can be a camera nowadays ?

[arc_de_triomphe]

Hello

I don't know if I can ask such a question on MalwareTips. You will tell me

I am looking for information and perhaps some of you could help me to get it.
I suspect some of you to be very resourceful

I am looking for a part of a documentary on the writer Patricia Cornwell in which she gives indirectly information about how small a camera can be these days.
She refers perhaps to a part of one of its novel. In this case if someone could also have the title and the section of the book.

So in this documentary, as I approximately recall, she says that two people (two characters of one of its book ?) have found some fingerprints (marks of fingers !) on a wall and then they think someone could have installed a small camera on the wall and they began to look for it.
She said they use a powerful magnifying glass and I guess she mentioned the magnification needed to find the camera.
She also said that without the clue of the fingerprints that give them an approximate location in the wall, they never could find the camera because cameras are too small nowadays.
I guess at the end they find it.

Behind all that is the question : how small can be a camera (for the purpose of spying) nowadays ?
I mean : one of those used by secret services. I suspect that they are incredibly small, no ?

Thanks for your information.

 

[Ink]

Surveillance doesn't have to be microscopic, in fact you can buy ordinary household good with built in Camera Audio recording and monitoring. If your phone or laptop gets compromised by malware or state-sponsored attack, could your webcam / microphone be recording in this moment.