There have been third party audits, but the conclusions have been that you can't know if it's implemented correctly or at all. Nature of closed source. Because you can't know where the keys are.

I get the doing business in their country. That is so difficult to overcome. I will not do it. Foot down on that one, and it does make it hard. My wife's family does the same as you mentioned. I just tell them they are literally paying for fascism. They don't care. Or you can pick from many of the ills of Meta products (energy use, AI, misinformation, or even simply making someone a billionaire by contributing nothing to society).

Makes it hard.