Re: SSH SOCKS proxy and data encryption while browsing website, how much privacy?
If you are using free proxies then don't assume anything is completely anonymous. If you are connected to the proxy via ssl, then your connection up to that point is secure. But if you are viewing content over plain http, then it is unencrypted from the proxy server onward.
Using a proxy service also leaves you susceptible things like DNS leaks which could leave you vulnerable. Your better option is a quality VPN service that encrypts all of your outbound traffic.
to more specifically answer your question: Even if you visit sites running on plain http via your encrypted proxy connection, your ISP should theoretically not be able to see your traffic.
However like I said, if you have any DNS queries leaking outside the proxy, then your ISP will see them and could figure out what you're doing.