The thing about Logitech (at least on Windows) is that it installs the updater as a device driver. So you cannot easily even block its internet access via firew

The thing about Logitech (at least on Windows) is that it installs the updater as a device driver. So you cannot easily even block its internet access via firewall rules unless you define one for rundll32.exe If you want to know more about it, just google "Logitech Download Assistant". There should be a device for it in your Device Manager and an LDA.exe process running.