This argument is absurd. Facebook has a settings page with a list of all the companies that have told Facebook they do business with you. That's the monetizable signal that Facebook is paying for.
It doesn't matter if they took your name, hashed it and then facebook reversed the hash via a lookup table. Presumably, the fact that they're doing the hash stuff is to give themselves plausible deniability when you tell them to delete all your personal information, and they decide not to.
Here's a sketch of the argument:
- We got a request to delete your info, so we deleted your name and email address and everything with the hash, including the fact that the hash doesn't want to be tracked.
- 10 ms later, data brokers started pumping information about the hashes back into our system, but there was nothing we could do to block it (we forgot the hash)
- We rebuilt your profile to high fidelity within a few minutes, and linked it to all your devices within a day
- The next week a shady app developer sold us info to link your real-world identity to the hashes, but we had to assume this was a new user that hadn't opted out, since we deleted your info.
It doesn't matter if they took your name, hashed it and then facebook reversed the hash via a lookup table. Presumably, the fact that they're doing the hash stuff is to give themselves plausible deniability when you tell them to delete all your personal information, and they decide not to.
Here's a sketch of the argument:
- We got a request to delete your info, so we deleted your name and email address and everything with the hash, including the fact that the hash doesn't want to be tracked.
- 10 ms later, data brokers started pumping information about the hashes back into our system, but there was nothing we could do to block it (we forgot the hash)
- We rebuilt your profile to high fidelity within a few minutes, and linked it to all your devices within a day
- The next week a shady app developer sold us info to link your real-world identity to the hashes, but we had to assume this was a new user that hadn't opted out, since we deleted your info.