Although they could have just sent it onto the intended target and gone quietly about their day, I'm really glad that Twitter made this an announcement. Do they have any kind of warrant canary system?
I guess it would have to work like a dead-man switch, in that not taking action triggered it. The way I understand the law is that they can force you to omit details about it i.e. "I refuse to comment", but they can't make you lie about it. I wonder if, believing that "omitting details" to be morally/religiously wrong, could you argue that it is preventing your freedom of religion?
Ultimately though, I agree that only a fully decentralized organization would work. I'd be open to other ideas, but I've never heard of one that avoids the issues that you mention above.
1. https://en.wikipedia.org/wiki/Warrant_canary 2. https://www.reddit.com/r/worldnews/comments/4ct1kz/reddit_de...