It certainly is a lot. It's enough for a drone strike. But almost by definition, if you have a back-end, there will be meta-data. There's been a few attempts

It certainly is a lot. It's enough for a drone strike. But almost by definition, if you have a back-end, there will be meta-data. There's been a few attempts at getting around it, with "one-to-many" (eg opaque PGP posts to Usenet groups), Mixmasters (remailers) or onion routing. None are AFAIK truly practical with a state-level adversary. e2ee is a good start, that doesn't mean you don't need to analyse the risks.