Ok, so I got lured into some Reddit lore.

This was pretty amazing. Guy wonders who is stalking him, one redditor picks up on the clues and suggests it's CO poisoning:

https://www.reddit.com/r/legaladvice/comments/34l7vo/ma_postit_notes_left_in_apartment/

Followup:

https://www.reddit.com/r/legaladvice/comments/34m92h/update_ma_postit_notes_left_in_apartment/

The ambien stories in the followup are pretty amazing.

> My former boss gave me one because I was sleeping badly, and my wife said that night I sat straight up in bed, grabbed a book and a cat and headed for the living room. She asked me what I was doing and I said I was going to go read to the cats because, "those motherfuckers need some culture."