This is something people are currently very upset with them for doing.
So they can make things convenient, or keep your data safe, but its hard to do both.
Even if your argument made sense with respect to the thing people are currently very upset about (which I disagree that it does), there is absolutely NO inherent right for FB to exist if they're unable to do both (if it's just "hard", well then get busy).
If I want to keep my data safe, they get to "inconvenience" me? That's ridiculous, if they can't keep my data safe, they don't get shit.
"But it's hard!"
cry me a river
It's an API to publish a notification - a similar API to that used to build the core app. There's no additional sharing of data than what's already happening running the app.