"Otherwise, you end up with Google's public-sharing bug (where you can share a private item publicly)." If you share something digital with someone, they can s

"Otherwise, you end up with Google's public-sharing bug (where you can share a private item publicly)." If you share something digital with someone, they can share it with someone else. That's just the way it is. Interfaces and clients should help you avoid doing that accidentally, and even make it slightly challenging (perhaps you need to write a new client against their API or something) -- but preventing you from exporting your own data, or data that someone has explicitly shared with you, is just not justified. It sounds a lot more like a convenient excuse for lock-in.