Is this the message: You are about to leave an encrypted page. Information you send or receive from now on could easily be read by a third party. [Check Box] Alert me whenever I leave an encrypted page for one that isn't encrypted. Yeah, don't worry about that. Just uncheck the box to get rid of the warning. It's just reminding dumb people not to enter username/password over an HTTP connection. You should only do that over an HTTPS (encrypted) connection, except that's irrelevant on hidden services, because the connection is fully encrypt from the Tor client on your computer to the Tor client on the hidden service server. You *should* use only HTTPS to enter sensitive info on clearnet sites though.