He Do the Prose in Different Voices

There's an interesting discusion here on the extra-textual relationship between reader and writer, and how blogs may affect this. I'm sort of reminded of those scam artists who accost you in the street, spend ten minutes persuading you they were at same school as yourself and so qualify as an old friend... and then ask you to lend them "a couple of quid"... On the other hand, which would be scarier* to a published author: a reader who says, "I feel I know you from your novels", or one who says, "I feel I know you from your blog"? Is there, in fact, a difference?

(* in a Misery sort of way, I suppose.)