Ever wondered how teachers always seem to know what you're up to at school? Well, it seems lots of them are getting a helping hand from CCTV cameras.
More and more schools are using CCTV in playgrounds, corridors and classrooms - and some even use them in the loos!
Some teachers think they're a good idea as they help with security and can stop problems like bullying and vandalism.
But others say they don't always know where the cameras are, and want to see new rules on how they should be used.
Lots of schools that use the cameras say they're for security, but also help to improve pupils' behaviour because they know they're being watched.
A group called the Association of Teachers and Lecturers said it recognised the benefits of using CCTV to protect the safety of pupils and staff.
But it added: "We are worried that some schools are not letting pupils and staff know where cameras are placed and what use they are making of any images.
"We would like all schools to have a strict policy about their use of CCTV which is clear to everyone."