There has been a shift in privacy with cloud storage. When everyone was using POP3 to get email with a 2MB quota on the mail server email didn't stick around on the ISP's computers for long - it was generally stored on a device owned by the recipient, and searching that required all the usual fourth amendment protections.
The Stored Communications Act [1] makes a distinction between unread mail stored on a server for more than 180 days, and does not require a warrant to access such email. It appears that read email still does require a warrant, however, as it is considered a "Remote Computing Service." I didn't know that until just now, and am not sure how the legal requirements for accessing that differ from a hard drive sitting on my desk at home.
A secure email product would be interesting. I'd be interested to know where deniability (i.e. OTR) would fit into your plans.
The Stored Communications Act [1] makes a distinction between unread mail stored on a server for more than 180 days, and does not require a warrant to access such email. It appears that read email still does require a warrant, however, as it is considered a "Remote Computing Service." I didn't know that until just now, and am not sure how the legal requirements for accessing that differ from a hard drive sitting on my desk at home.
A secure email product would be interesting. I'd be interested to know where deniability (i.e. OTR) would fit into your plans.
[1] http://en.wikipedia.org/wiki/Stored_Communications_Act