Thanks for your views. Here I want to suggest you that visit more and more blogs of people as you can,comment and upvote their posts. An other the easiest way to interact with friends only is to create your own special tag! Tags are used to create a feed of posts, so if only you and your friends are using your "secret" tag, then the chances of anybody listening in are very small. Remember that there are hundreds, maybe thousands, of messages every minute; by creating your dedicated tag you can filter those out and tune in to your friends.
Best of luck!