Because they’re rich and have lots of nice things worth stealing. Because many of them are celebrities or high ranking CEOs or chairpersons who value privacy. Some of them may be paranoid and want to protect their children and pets, and avoid break ins. I would imagine they would have more security features such as cameras and security.

I know someone who works for a celebrity actor (no, I don’t know who) in Greenwich and they have to punch in like 3 different codes to get past multiple checkpoints to enter the property and house. They aren’t allowed to take photos, not even a selfie, on the property. Very protected.