They are testing a new multispectral imaging pod on the U2 currently, thats not to say they aren't doing real surveillance over California with it, but thats the cover.
USAF Plans To Test A System Called 'Symphony' Inside An 'Irascible Pod' On A U-2 Spy Plane
http://www.thedrive.com/the-war-zone/22469/usaf-plans-to-test-a-system-called-symphony-inside-an-irascible-pod-on-a-u-2-spy-plane