How everyone is connected!

I am planning to create a website that can connect every person they can join with their family tree.

So If I try to create this website that can tracks every person and what all features do I need to add Let's think about it.

1.Everyone should add with their FB account

2. People can modify the tree whatever they want But We cant check the validity of the tree

Functionalities of the tree:

1. People can create a tree
2. Map people with other trees
3. Merge the trees or join them
4. The validity Of any node(Person) can be created when they have a major contribution and he is there in a lot of trees
5. People can try to be anonymous