I've read a few books and listened to podcasts on this subject that made me want to check the locks twice. 'The Stranger Beside Me' by Ann Rule is a classic, obviously. It's about Ted Bundy, and the chilling part is the author's personal friendship with him before knowing he was a killer. It completely reframes those ordinary, charming interactions.
But the one that really got under my skin was a deep-dive into the cyberstalking of 'Lena' in the book 'Nobody's Victim'. It details how an ex used technology to terrorize her for years, from hacking her accounts to swatting her. The modern, faceless nature of it, the way it invades your supposedly safe digital spaces, felt more immediately plausible than a guy in a dark alley. It's the banality of the tools used for such profound harassment that's so unsettling.
That's the stuff of real nightmares, I think, because it strips away the illusion of sanctuary.