Dan Luu on Nostr: Does anyone know what, specifically, is being referred to in this comment about how ...

Does anyone know what, specifically, is being referred to in this comment about how Facebook claimed they has too much data that's spread out too much to be able to return an inventory for a particular person?

I could imagine a response like this for GDPR data requests or something, but I'm looking for a reference with an actual quote from Facebook on this, not just the generic idea that this is happening.