I'm not unreasonably worried about my coworkers, compared to a software-controlled camera they'd be wearing on their heads and pointing at our code, internal docs, customer information, etc.

And yes, if someone made a habit of pointing their cellphone camera at the screen all day, I would ask them to please knock it off.

I don't trust Facebook installing cameras in our workspace, or trust that they couldn't be compromised by another party who might want to watch what we're doing.

Indeed. Time and time again Facebook/Meta has secretly or openly breached privacy boundaries for their own gain. They cannot be trusted with user data.