Introduction: Closing the Windows
Smart cameras are convenient, but they are also a target for hackers. If a camera has an IP address on your network, it could potentially be 'seen' from the internet if your router isn't set up correctly. IP Filtering is the most effective way to ensure that your private life stays private.
The Trusted-only Mode
Most high-quality cameras allow you to set an 'Allowed IP List'. You can tell the camera: "Only accept connections from this one specific IP (your phone's static IP) and ignore everything else in the world." This makes it impossible for someone in another country to 'stumble' upon your camera feed.
Conclusion
Your camera's IP is its front door. Lock it tight with IP filtering. Check your camera's visibility here.