Those who are concerned about this have three options:
* make the effort to learn how to set up and maintain your own instance of your chosen federated social app. You get to decide exactly what data is and isn't shared with the network. You don't depend on the goodwill of any third party , or their security competence (just your own).
* find a geek you know, and get them to host an instance for you. There is a third party, but it's someone you personally know and presumably trust.
* find a public instance run by a collective or organisation you trust to care about your privacy and know how to protect it, eg some people might trust the motives and competence of EFF, or their country's civil liberties organisation (eg ACLU in the US), or a collective like RiseUp.net or Disroot.org.
While export/ import of accounts between instances is an unsolved problem at present (Hubzilla can do it using Nomadic Identity but only between Hubzilla instances), the devs of all the federated apps are aware of it as a major pain point, and work is underway to implement it. In the meantime, if you're willing to go to the trouble of re-following and nagging all your followers to re-follow, you can move between the 3 options above at will. FB and other datafarms offer you none of these options.
* make the effort to learn how to set up and maintain your own instance of your chosen federated social app. You get to decide exactly what data is and isn't shared with the network. You don't depend on the goodwill of any third party , or their security competence (just your own).
* find a geek you know, and get them to host an instance for you. There is a third party, but it's someone you personally know and presumably trust.
* find a public instance run by a collective or organisation you trust to care about your privacy and know how to protect it, eg some people might trust the motives and competence of EFF, or their country's civil liberties organisation (eg ACLU in the US), or a collective like RiseUp.net or Disroot.org.
While export/ import of accounts between instances is an unsolved problem at present (Hubzilla can do it using Nomadic Identity but only between Hubzilla instances), the devs of all the federated apps are aware of it as a major pain point, and work is underway to implement it. In the meantime, if you're willing to go to the trouble of re-following and nagging all your followers to re-follow, you can move between the 3 options above at will. FB and other datafarms offer you none of these options.
EDIT: formatting