There's no sync (at this point) and no account creation by design. It's all stored in your browser - I suppose in that regard it is not 'online'!
Sync may well be coming, but I'm not yet certain how to do it securely. That being said, import & export is available now, so it can be manually sync'd.
it would be easiest yes to use something avalablee to people for free where good encryption things are present. but i suppose a lot of the world is waking up to the fact these things aren't so nice really, and offline storage for personal things is better.
it would be cool to have some export or import button to save everything into some kind of archive, then you can move it between offline machines and import it into the browser to use it there.
Sync may well be coming, but I'm not yet certain how to do it securely. That being said, import & export is available now, so it can be manually sync'd.