Security cameras are an optional addition that some nomads like to add to their vehicles for additional safety and security. They can be permanently wired in for a view of the interior or exterior of the van, or portable wireless cameras that can be moved around as needed, even being placed away from your van and pointing back toward your vehicle.
Exterior cameras
Van-view cameras
If you have a wireless battery-powered camera that can be viewed remotely from your phone or a dedicated screen, when you are parked for a while you can hide the cameras in trees, etc., and point them at your van. This allows you to clearly see anyone or anything outside your van, and it will generally provide a better view than a camera attached to your van. Just be sure to grab your camera before you drive away, or it will be an expensive loss! Van-view cameras are also subject to theft; if someone finds it where you have hidden it, they may just take it.
Interior cameras
If you have full-time internet in your vehicle, you could install a motion-sensing camera that will upload images or video. This would provide some evidence for the police and your insurance in case of a break-in. Some people with pets living in their vehicles get internet-enabled security cameras so they can check in on their pets while away from the vehicle.