It scales with popularity and changes with demographic. I’ve known non-famous CEOs who needed security details when visiting any conference or public event because they had stalkers who would reliably appear and try to get close to them.
Even on HN I had a stalker. With a previous handle I wrote a long comment about a subject that someone found insightful. They scanned my whole comment history until they found a comment where I mentioned a company I had worked for, then did a process of elimination to figure out who I was, then started contacting me through email and other channels demanding more conversation and writing on the topic to answer their questions. It was very unsettling. I’m now more careful to leave out any identifying facts on HN.