I'm not sure how Cloak (getcloak.com) isolates captive portals, but one of their features blocks http traffic (but allows https traffic) until a tunnel is up. G

I'm not sure how Cloak (getcloak.com) isolates captive portals, but one of their features blocks http traffic (but allows https traffic) until a tunnel is up. Granted, this doesn't help for things like unencrypted SMTP, but it's a step in the right direction.