[lmm]

If you could get enough people doing it, yes. But in practice the only people who would care enough would be the people the governments want to watch. Even a decent chunk of the crypto community would rather dunk on a cryptosystem they don't like than actually encrypt their emails (although of course how much of that is the NSA disrupting things is an open question).

[elcritch]

I actually sorta think unencrypted email has been a boon for society as both corporations and government agencies have left paper trails that helped expose their misdeeds later.

[BlueTemplar]

I thought there were wildly popular messaging apps now that were encrypted by default ?

[lmm]

There are, but basically only because of Facebook, who seem to actually care quite a bit about crypto and have the clout to make things happen. I don't think it's coincidence that they're also the main sender of encrypted emails (you can set your PGP key and then they'll use it for all their emails to you).