Why is the Southern District of California -- i.e., San Diego -- so overwhelmed with federal criminal cases, you might ask? Well, one reason is because it's so darn easy to make money down here, albeit illegally. You drive down to Mexico, pick up some stuff, sneak it across the border, and sell it to Americans with a voracious appetite for your product. It's relatively easy money. As long as you don't get caught.
The stuff you can easily pick up in Mexico can be sold in a heartbeat for double or triple the price up here. I think you know what I'm talking about.