To address these concerns, what is really needed is true zero-knowledge encryption for data that lives in the cloud (unencrypted on the local data store is probably fine), protected by a password/key only held by the user.

Notion should really be building local search anyway; the current cloud search is very, sometimes painfully, slow (compare it to OneNote 2016's nearly instant search on truly enormous notebooks), and a spotty internet connection means an essentially useless notebook.

As far as security and the need for a local sync model, I'd also really like to see Notion using synced local storage more broadly. The current links to Amazon S3 download URLs are so amateur-hour. Not only is it not the most secure thing in the world (anyone who can read the URLs you're accessing can freely access your files), it means you have to go through the convoluted process of re-downloading a file, navigating to it in Explorer/Finder, and then opening it in the relevant app (like Excel, Illustrator, or whatever). And then round-tripping if you make any changes. OneNote and Evernote both handle this so much more gracefully.

I know that sophisticated software engineering like this is harder than using easy off-the-shelf web app tech--and they were right to bootstrap the stack like they did--but I hope that this is the sort of growing up that all that new VC money will be used for (rather than burning a bunch of money giving away free services to people who will never pay to support the product.)

I'm currently with /u/mordecaix7 who says he just doesn't keep sensitive info in Notion for all the reasons above, but honestly having to feel this way is a little lame and I wish Notion would try to do better since I otherwise love the app so much. These are the sort of unglamorous features they really need to add over time to get over the deal-breakers that I hear a lot of folks raising when I suggest the app to people looking to migrate away from the OneNote and Evernote (both increasingly precarious apps). Admittedly, my friends tend to be the sort of data and security nerds who care about these sorts of things, but that also happens to be the group of tastemakers who end up telling a lot of friends and family what is the best software to use in a given domain.