Some argue that if a device is broadcasting on a public IP with no authentication, it is, by definition, public. The camera owner has chosen (through negligence) to publish the feed. Security researchers use dorks like this to highlight the scale of the problem.
: This term suggests a connection to a web-based interface used for viewing video feeds, likely from IP cameras or similar devices.
Go into your camera’s web interface (often via the same viewerframe page, but from inside your network) and ensure that "Allow anonymous access" or "Public view" is unchecked. Require a username and password for every video stream.