DoPlayerDevCam is a method which allows you to block or modify a player's attempts to use a developer camera.
If you want to limit access to the developer camera, you can refuse to call
base.DoPlayerDevCam() In this example, we use a player's Steam64ID (you can find yours with this site) to grant access to the developer camera.
How you decide a player may be granted access to the developer camera is up to you. You may wish to set a password, or limit by Steam IDs (seen above). You may also wish to create a new developer camera from scratch!