Yep... what's happening in Oakland, is unfortunately not a surprise. The last 10 or 20 years in particular have seen increasing militarization of local law enforcement all over the country. Coupled with Oakland's history/notoriety for abuse, it was a recipe for disaster.
I agree, ever heard of that big as armored car in the 90's that busted through houses. "The war on drugs" was a huge excuse for the police force to become much more armed.