> I wonder if wealthier areas are targeted?

Maybe, but it's also probably still extremely rare and internet discussions oversample people who have been victims. I've only known one person here in LA who's had any of their packages stolen in the past few years, and that one turned out to be due to a bizarre personal vendetta.

Lower class neighborhoods usually have a lot of safe guards built up over time because “they are used to the problems” whereas middle and upper-middle class neighborhoods are just getting their first taste of the problem in the last few years and are still pretty soft as targets. If you are a package their, go after the rich people who are less likely to have some kind of protection.