Would it bother you to read something important on Facebook? For example, last year when DH's cousin (2) died, everyone including close family read it on Facebook. Same with my cousin. When her young baby died from SIDS everyone including close family read it on Facebook.
I am torn about this. If something that devastating happened to me, I would not want to call each and every person I knew and tell them something tragic. On the other hand, this is not how I would want to learn about something serous.
What about less serious things? I saw someone (distant relative) complaining recently about finding out their sibling was in the hospital is seriously sick, and she had to read it on FB. Other people responded they were thankful they found out at all.