MIA Yet Again

I've written about this before, but it still irks me...people who I've emailed with or have blogrolled me, who suddenly either shut down their blogs entirely, or take them private with no warning and no follow up.
I've lost The Story of M, which I enjoyed reading, and Joy, shared, which had blogrolled me and then went private, perhaps over the weekend.
I do understand that nobody has any concrete obligations to anyone here, but common courtesy should prevail.