There are lots of ways to secure a wireless connection. One of the more popular ways with business WLAN's is to not secure the wireless connection at all, and run everything over a VPN connection. The VPN traffic is encrypted and is therefore sniffer safe. Authentication is left to the VPN.
However, all the one's I've seen have a splash screen that greets the casual hacker with threats of prosecution if they continue beyond the initial connection. You're expected to fire up your VPN software, or connect via SSL/TLS to an obscure authentication server. If you don't know the name of the server, you don't go anywhere. I guess someone is setting up a similar system but without the splash screen warning.
You can usually get a clue as to who owns the system by the SSID. If it's your local police department or government, I would tread carefully.
There are also various services that provide VPN terminations. I blundered across: