Good question. Probably you need to send a data request, so they can provide you with info they have about you. But based on what should they search in their da

Good question. Probably you need to send a data request, so they can provide you with info they have about you. But based on what should they search in their data warehouse? IP? Cookies? Interests? Leaked email? I guess one way to avoid shadow profiles would be to block FB scripts/cookies on pages you visit, so they won't track you.