Earlier quoted context omitted.
Maybe engineer a service that is harder to wiretap? It is not easy, but they have some of the best computer scientists on this planet working for them. If I were them, I would start somewhere around here: http://crypto.stanford.edu/adnostic/adnostic.pdf
It's not directly apropos this particular thread, but Google has engineered an email service that is particularly difficult to wiretap. To wit: (a) They're the Internet's foremost adopter and proponent of DHE ciphersuites, which drastically reduce the impact of losing the RSA key that underpins most site's TLS security, and, just as importantly, forces adversaries to actively MITM every connection in order to decrypt…
Actually if someone sends an email to my Gmail account using his ISP SMTP server, is the connection between the two SMTP servers likely to be encrypted?