title: Is it possible to read, using open graph, on a server side if user is logged in to facebook?
body: <p>Someone is logged in to Facebook and than goes to my website. Is it possible to read on a server side if he's logged in to facebook now. I need to show different fields for a comment form. At the moment I'm using Rails and <a href="http://github.com/jugend/fgraph" rel="nofollow noreferrer">http://github.com/jugend/fgraph</a> plugin</p>