The "Security Camera" is the severed head of a zombie that fits the purpose described in his name: The player can see their field of vision because it shows up as a yellow light that will turn red when the player stands in it. If the player stays long enough in the vision of the security camera, it will start screaming, alerting all the undead in the level. They are fixed to the ceiling thanks to a big black chain, which makes them stationary.
Security Cameras have no way of harming you on their own, their only purpose is alarming the other enemies in the level. They are also very weak and can only endure one shot. Destroying them which a throwable melee weapon allows you to reuse the weapon, unless it's stuck.