[Closi]

There are possibly other options, such as:

1) Providing end-to-end encryption on user data travelling from Europe to outside Europe.

2) Your option for number 1, but then allowing users to freely consent with their data to be shared internationally (which they can then revoke later if required).

I'm sure there are others... Also IANAL but a social media post may be covered under the "legitimate interests" scope of GDPR (but facebook's tracking data would certinally not be covered).