This is one of several reasons why I keep all my cameras and any other IoT devices on a separate VLAN that has no access to the internet and no access to the rest of my home network. The only bridge is my DVR server, but that’s something I can’t get around.

Before it was set up this way, I saw a huge amount of requests on my DNS server from the cameras, each one resolving the manufacturer’s domain name. It was probably innocuous, but why take the risk? There is absolutely no reason whatsoever that a security camera needs access to anything.