I just tried FaceNiff on another PublicWifi, where you actually can connect, but have to pay to get outside connections.
Now the interesting part: While FaceNiff was running, i could surf on that hotspot... without logging in. I could even access the internet from my notebook, when that was also logged into the wifi.
Anoter time, when i started FaceNiff, it completely jammed the network. Suddently the internet wasnt working anymore, for everyone on the network (pretty crazy faces around me)
Whys that happening?