Hello fssbob,
it does few more things.
It prompts a warning when a new router is found on your network as someone could be trying to redirect your traffic.
When you change a network, e.g. moving from Internet Caffee to a different location, it prompts you whether you want to monitor this new network. If you agree, it runs a very quick scan to check for vulnerable routers or other security issues on the network. It remembers the networks you agreed to monitor so when you join them later on, they should be automatically rescanned.
Best regards,
Jakub
