I understand that connecting to a wireless network using a WEP/WPA key is also encrypting the data you send over the network, hiding it from potential sniffers in range of the network (please correct me if I am wrong here).
Is an unsecured wireless network (that is not secured with a WEP or WPA key), but relying on web authentication via a Captive Portal a safe network? Is data that I am transferring (after authentication) over such a network transparent to the outside world?
How about users also authenticated over the Captive Portal web authentication page? Can someone sniff the Captive Portal traffic and get hold of the data?