I don't know what this Anon refers to but I can tell you about the Worldwide hum.
It's a phenomenon and spans the globe. Testimonials here: https://thehum.info/
If you hear the hum, you'd know that typically it ramps up at about 3am. Increased EF waves/vibrations disrupt sleep, cause anguish and irritation, and also increase violent tendencies. Folk's sleep is being disrupted.
Another reason to LOVE Night Shift!