[bigiain]

Even in your scenario, I can see some utility. A paren or spouse who has your email password still can't reset your Facebook password without your PGP keyphrase password as well. That's perhaps not a significant additional barrier, but at least it's a much less commonly used password/phrase than your email account...

[patzerhacker]

Again, the big problem for abuse victims is getting the shellac beat out of them for disobeying their abuser. This encryption does nothing to enable an abuse victim to switch on notifications as the (now grand-)parent post I was responding to was insinuating - abusers on that level don't care what the message says. They are going to interpret any message they can't read as a message that goes against 'their rules'.