I grew up in the valley during the late 80s and early 90s. My family moved to Malibu, and I moved to the Westside. After my wife and I got married we bought our first house in Simi Valley (we love it here, West of of San Fernando Valley). Goign back to the San Fernando Valley has been a culture shock. I don't even recognize it anymore.
Shopping carts strewn about, signs in Spanish, and shopping centers that look like they came from a 3rd world country.
Was quite saddened by it actually. I wonder how long Simi Valley has to go until the Westward/Northward march continues for those of us who speak English (and hell, I'm not even white, my parents are immigrants to this country -- legal).
Don't know if it's still the case, but Simi has traditionally had a high population of law enforcement folk living there, which helps. They tend to be extra vigilant, and they recognize signs of problems before most others do.