No our posts are not automatically on Twitter. The way it looked to me is that you have to log into to Twitter & then you have the option to share a particular link to your Twitter followers.
If you look at the url in your browser it shows this is thread 1868399 and if you click on the Twitter link it offers to share only that link:
http://www.medhelp.org/user_photos/show/323059?personal_page_id=1282072
Thanx for clearing that up! Not that I mind, but I shared uber personal stuff on here when I was treating, ya know?