When my wife and I go out for our nightly walk, we often pass by this area of Downey. It's the area just outside the police department.
At first we thought the younger set had found a new hangout. But everyone was on their cell phone. Then we found that everyone is looking for Pokémon monsters. You can learn more about the game everyone is playing here.
They even have people riding around to plant eggs of the monsters so they can pick them up later.