While celebrities quit Facebook, others say they feel trapped in it

SAN FRANCISCO — Some well-known people said this week they were deleting their Facebook accounts: pioneering tech journalist Walt Mossberg, author and law professor Tim Wu and singer and actress Cher, who was re-upping a vow she made in March.
America, though, doesn’t appear to be joining in lockstep. Nor does the rest of the world.In interviews and on social media, an array of people said they haven’t deleted their accounts because they either see