California is a notorious high-tax state that aggressively pursues its residents who move to another state and contend they no longer owe California taxes. The main bone of contention usually involves stock or security sales, where the taxpayer argue they were living in another state (usually a no-tax state) when the asset was sold, with California asserting that the sale occurred while the person was resident in the state and taxes are owed. 

(April 2024)