But how do you do that without essentially downloading the whole social network to your local machine? Are other people's comments, quotes, likes, moderation signals something that should stay on the server or should be synced to the client for offline use? In the first case, you can't really use the social network without connecting to a server. The second case is a privacy and resources nightmare (privacy, because you can hold posts and comments from users that have deleted their data or banned you, you can see who follows who etc. Resources, because you need to hold the whole social graph in your local client).