Other users can’t change your trees unless you allow them to.
At Ancestry.com, Findmypast and MyHeritage, you build your own individual trees. Other users can’t change your trees unless you allow them to. At all three sites, you can choose for your trees to be publicly searchable and viewable by others, or private (seen only by you and those you specifically invite). You can search other people’s trees, too. This may lead to connections with fellow researchers and new information about your shared roots.