i just booted up ubuntu for first time and connected to wifi. i've come from windows where when you connect to wifi you choose to make it a 'home' or 'public' connection. i can't find this option anywhere so does ubuntu automatically treat all wifi connections as 'public'. i use from a router in the stairwell of a small apartment block used by others, so when i was using windows op system i always made the wifi 'public'
As I understand it, "public", "work" and "home" simply turn on differing levels of a firewall-like scheme, allowing or denying services, supposedly keeping your computer safe from attack.
If you're interested in this type of "protection", you should investigate a Linux firewall configuration program like
firestarter, which will allow you to do the same thing, but with much more control and understanding.
In my opinion, this isn't much use compared to running Linux and using WPA encryption to the router. If you really want security, get an encrypted VPN like airvpn (airvpn.org) for a low cost. If the connection to the router isn't encrypted, get a VPN, else everything you send is easy to intercept.