I'm rather unfamiliar with the WordPress.com procedures for following blog. Generally, I never even think of this until someone follows me. Then WordPress automatically suggests that I follow them, and I make a choice.
But what about those (for me rare) cases when a "Wordpress follower" signs up without providing a blog URL. How does WordPress even know that such a follower is a WordPress member? I would presume that WP detects the membership because the new follower is logged in. But how then, and why, am I prevented from obtaining the new follower's blog URL presuming it exists?
Blog url: http://songbook1.wordpress.com/