In the past 6 days, "facebookexternalhit/1.1" has requested my robots.txt 592,489 (edit: used to say 701,311) times. That's more than once per second around the clock. It's coming from FB's IP range, so it's not someone else masquerading as them.
What's going on, @zuck@threads.net? What's so interesting in my robots.txt?