Opt out
That is how Facebook et al word the T&C so they can slurp with impunity. Personally I think that is shady. I would put a notice like:
If you sign in with _____________, they will retain your data and that ACME App has no say whatsoever how _____________ retains and uses that data. It is your responsibility to opt out with them, not ACME.
Biting the hand that feeds IT
