By keeping documents in the cloud, data is readily accessible and easy to share. Collaboration no longer requires us to email revisions back and forth, and subsequently stitch them together. But, there's also a downside. Because sharing is now a passive process, it's easy to forget who can access those document.
So, if you're working on something that you aren't ready to share, you may want to consider working on it locally before you store it in the cloud. While cloud providers make it simple to view and edit documents, it's often hard to figure out who can see what.
Beware of people sharing document templates created in the cloud. Because they started the document, it's likely that they'll continue to have access to your drafts unless you revoke them. But, since that's not always explicit, it's easy to overlook.