Video Surveillance doorbell camera

[Yashar Fred]

I have a rental property with security doorbell and floodlight cameras which were there before tenants moved in. After tenants moved they are objecting to the security cameras (doorbell and floodlight) even though I have given them shared access to the camera content and it was mentioned in the contract that the premises comes with cameras. 
is it legally allowed to use surveillance cameras 
What is the best course of action in your experience