I have no problem capturing packets on various wireless hotspots but there are a couple in my town that I just cannot understand why packets aren't being captured, other than those of my own. These are "open" networks (i.e., no WEP/WPA/etc. protection) where you obtain a username/password from the administrator, connect and then open internal page to log in using those credentials. Only then you get access to the Internet.
Here is what the traffic looks like: http://img821.imageshack.us/img821/3195/snapshot2d.png
Could someone please guide me in the right direction as to how to "decrypt" the traffic? If there's no encryption, why don't I see anything?