Actually, I did this myself. Last year, I was hospitalized with the mother of all infections that infected both of my hip prostheses. While my b/f or myself (if I could) called my dad and sister to give them updates, my friends and boss got updates on Facebook.
If we had to call everyone, it would have been impossible to handle.
Later, after I was released from the hospital and rehab 8 weeks later, I dealt with people on a more personal basis.