I recently joined Diaspora*. It’s a decentralised social network, so anyone can start a pod (a Diaspora* server). Or you can sign up on an existing pod. The idea is that you have control of where you keep your data. In the best case, you actually have it with you in your own pod, but otherwise you can choose any volunteer server that you trust.
The pods are interconnected, so you can share and keep in touch with people even if they’re on a different pod. In the beginning, it takes a while to figure out how things work, but I think it’s worth it.
My main barrier to leaving Facebook is currently the Network Effect: basically, all my friends are on Facebook so I have to use it to keep in touch with them. But I’ve decided to start Diaspora* anyway, because somebody has to make the first move.
I’m planning to write a piece on Diaspora* soon. Hopefully that will make things easier for people who want to join. I can give you the link when it’s ready, if you’re interested.