> In order to preserve the usefulness of those models and the hundreds of millions in R&D spent to develop them, you have to carefully understand exactly what p

> In order to preserve the usefulness of those models and the hundreds of millions in R&D spent to develop them, you have to carefully understand exactly what products and algos will be affected by just deleting a single record. Indeed, that sounds like a hard problem. So the question becomes "how much of the hundreds of millions in R&D are being allocated to solve the record-deletion problem?". I'd like to see spending reports, new research publications from Facebook (e. g. retroactive record-deletion, attempts to build models that are robust to deletion, attempts to build k-anonymity into models from the start). > I know there are more nuances here, but I think there are some challenges Facebook has in implementing this, and business wise it's a drain on resources that will hurt them. I can give Facebook the benefit of the doubt and suppose that they're trying to figure out how to transition smoothly without destroying their models. But I'd also like to see a hard timeline when they promise to roll out user.delete.all.data() anyways (business value be damned). The real test of whether a company really "takes your privacy seriously" is whether they ever reach a point where privacy becomes a priority, i. e. whether there are decisions to do the right thing even when it could be bad for the bottom line (under the current business model).