So if governments are sniffing on high entropy traffic, could we just send normal seeming (SSH or whatever) packets with the payload coming from /dev/urandom? Would that be a denial of service?
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).
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.
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).
When they find a way to "decrypt" /dev/urandom output into, you know, whatever is expedient for them at some future date, do you think a secret judge in a secret court is going to believe that you were just moving around random noise for the lulz?
