I got #meshtastic nodes working as advertised and it's super freaking cool. Here's a picture of my test setup.

Messages come from phone and go to the wifi access point (in my case, a raspberry pi) to the Meshtastic node. That, in turn shoots it through the medh network using LoRa, and it goes from the recipient Meshtastic node to a computer via serial (USB).

Messages are encrypted across the LoRa link by the Meshtastic nodes. My WiFi has WPA encryption to protect it between the phone and the node that is on WiFi, however I believe the router and anyone connected to that access network can see everything in plain text.