It always make me think (probably I am just over thinking) since I am new to HA which hardwires to my router via ethernet and it has Internet access. My question is what stops the devices that are integrated with HA from talking to some random cloud server) ?
I have not connected any of those smart devices via wifi its all on Zigbee
You can use your firewall/router to stop any if your networked device to go to the internet.