Preventing other users sniffing passwords

[Guest]

Hii  all
I use the pfSense 1.0.1, it is very good but I have a big problem that  the users at the captive portal enabled interface are all in the same subnet and can talk to each other without passing the firewall . I want to  prevent other users sniffing passwords and network traffic .
I need some help please
:-\

[Cry Havok]

Well, you can only solve this for traffic passing through or to the pfsense box - simply enable and require some form of VPN, either IPSEC or OpenVPN.