late stage syphilis is tied to 'delusions of grandeur' in which the sufferer comes to believe they are bound for fame or tied to someone famous. It used to be more common in the 1930s and 40s before treatments improved; Hitler is the most famous example from that era. But that isn't the only path to stalkerism. By boss at the studio was in his 70s and told me stories about the 1940s -- this stuff is not new and there used to be fewer celebrities so more stalkers and mentally ill people had fewer targets. Some of the craziest incidents happened to Shirley Temple.
I worked security at the 1984 Olympics and ran down a guy who had slipped in without a ticket. He had really bad energy and was angry with me right away. Spoke to me in German and then got even angrier when I answered in German. I was bumping bodies with this guy and I was unarmed. Watching his hands and waiting for LAPD to come to us. They took him and my boss there later confirmed that I did the right thing. Turned out the guy was stalking Steffi Graff who was barely 15YO at the time. Nine years later he stabbed Monika Seles during a televised tennis match in Hamburg. My blood went cold when they showed that guy's face on the news. Not the kind of face and hairline you forget. I don't know if he had a knife when I stopped him but it definitely seemed like a possibility.
NYC is generally a good place for celebrities to live because people don't hassle them or behave the way people in LA do. John Lennon is of course the notable exception but his attacker came from Hawaii to do what he did.
NYC is a much better place for the rich (and everyone else) to raise their kids than LA is.