Spying is a fact of life. We laughed about it in the 1960's with Allen Funts' "Candid Camera" Fast forward to the 21st century.
In the name of the God and excuse of Public Safety, they are installed in more places than you know! They are easy to manufacture and cheap to install and distribute. A key question is whether they take stills or timed videos.
In places like London they are placed everywhere. In transportation centers, central terminals, streets highways and other locations. In this place they were introduced as a result of indiscriminate bombing by the IRA and other terrorist groups.
It's only going to get more intense. They are located in
- ATM's to record financial transactions for accounting purposes. But also illegally to spy
- Some elevators to catch acts of random violence
- Busses, classrooms, hallways and most areas around schools. Publicity over violence has caused this
- Traffic lights and overhead mounts as well as toll stations for traffic counting and monitoring
- Chillingly your own laptop camera if taken over
- Here's a real surprise - hospital rooms, Patient safety has resulted in this intrusion
- Hotel rooms while not officially bugged can be compromised by an unscrupulous person also
Camera and byproducts like film register high in our activities niches and affiliate opportunities as well. It's a mainspring of 21st century commerce!
More detail if preferred at the source.