I've just noticed that this text can be found in every single one of my posts on my website, collegeinfogeek.com. It's usually invisible, though a CTRL+F can find it. However, on a couple posts, it's totally visible and messes up my content. Some Googling on my part helped me to find out that most people experiencing problems with this message are working with Facebook connect.
Here's an example of a post with the problem: http://collegeinfogeek.com/2011/02/22-more-awesome-study-albums/
To rule out the Facebook possibility, I removed the ShareBar from my site as well as the Facebook Like count from the sidebar. No dice - the message is still there. Any idea why it's there? Does anyone else have this problem?