Maybe I was lucky, but I can't remember any teacher I had who shared inappropriate personal information the entire time I went through the public school system, with one minor exception: I had a coach in high school who found ways to inappropriately share his devout faith with the team.
My second grade teacher changed her name at the beginning of the year, and had a bulge in her belly at the end, so she couldn't really hide her big personal life events. My fifth grade teacher had students over once a year for a BBQ, so we met his wife and kids. I did have a science teacher in middle school who talked about his wife all the time, but it was part of a schtick, and I'm not sure if he was even really married (he always talked about how fat his wife was, and he had a picture of a gorilla on the wall that he said was her, but in truth he was the one who was extremely obese, and this, I suppose, was the joke - the fat guy who couldn't see that he was really talking about himself). Both our German teacher and speech teacher in high school are very friendly with former students, but these are friendly relationships that developed after graduation, and grew out of what were appropriate and valued teacher-pupil relationships while we were there. I didn't know a single thing about either of their personal lives until I friended them on FB many years after I left high school.
If we really have an epidemic of teachers who are sharing their personal lives with students, that's an educational context with which I am totally unfamiliar, and I imagine that's the same for many of us.
