Are you using it? does it work? when I tried to use it some long time ago, it was unusably broken (asked me to validate my account by recognizing photos of some friends, but each photo was showing as a blank white rectangle).
Possibly the most famous darkweb URL.
I feel like Dread Pirate Roberts would have something to say about that.
I think GP means that facebook spent a lot of CPU cycles getting an onion address that is so human-readable/memorable; I don't remember what the old Silk Road's address was but I think I'd remember if it were silkroadcorewwwi.onion