Yesterday I was in the library looking at the 2001 version of "Genealogy for Dummies" and they had a section on privacy. They said it could be very harmful to have certain information available online. Private detectives, con artists and other potentially troublesome people can use search engines to look for living family members.
I went back to my Wikitree and changed all of the living relatives to "Unlisted" and several deceased to "Private." Right now I use it mainly for my own information, but I don't want to put my family in harm's way. On the Wikitree site, the default setting is automatically "Unlisted" for kids under 13. I think the default should be under 18, not 13. The wrong information in the wrong hands could even be dangerous: For example, a disgruntled former spouse might hire one of those detectives to track down an ex who wants to be left alone.