Your analogy breaks down in that the leaks are are a result of a breach, most certainly a violation of CFAA. No current understanding of law shares your opinion that because it's an open protocol that you no longer have agency over the content. Security measures were put in place, though certainly not enough to prevent a major leak. Though I hate bringing in analogies, you're not more culpable for your house being broken into just because you don't have 6 cm steel shutters for all openings; it's certainly more secure, but illegal access is illegal access.
I say this next part not to be demeaning but to state an assumption of mine, but I'm going to assume you probably dislike the CFAA; I do as well, but to say there's no theft possible is a naive notion in the face of labyrinthine laws. The world has been dealing with email breaches since your average hacker got a home connection fast enough to move a few megabytes of data without timing out. The law's opinion on theft of email is incredibly different from your own.