Introduction Videos and text
I think Intro to FamilySearch Videos and text should explain to new members and users of familysearch, that this is a public tree, that any member can change the data about any person in the tree (except the pages of the read-only persons).
It should suggest a few easy ways to keep your own private tree:
1) Besides using FamilySearch, also keep it on paper in your own personal files
2) Besides using FamilySearch, also find a computer program which can keep it private for you on your computer
3) Besides using FamilySearch, also use ancestry or other online tree which can be kept private or shared, which, either way, cannot be changed by others