I'm gonna ask a question which includes both SSL and VPN. Though, question is same for both.
For SSL, i logged into a forum which offers/supports SSL encryption for secure authentication.(like email services, banks did).That way, the data between me and server(if server is properly built in any cases and service is reliable)is secured and even ISP can't display it. Then, i started a thread as a registered member of that forum. Can other registered members display the thread content?
Same question is valid for the VPN as well. Can other registered members display the thread content?
If they can, where is the security on the content except login information case? (for VPN and SSL). I mean perhaps ISP at that moment can't examine it but members and web site owner see everything.