In California, unless there is a contract specifying otherwise, all employer/employee relationships are at-will.  That means that you can quit anytime and they can fire you anytime. The main restrictions are that you can't be fired for discriminatory reasons (i.e. race, gender, ethnicity, religion, disability).  In California your employer can fire you five years later for stealing a candy bar.  My guess is they wanted to down-size and your candybar incident put you in their radar.  Unless you can show that they really fired you for some other reason (which is hard to prove) and that reason happens to be protected by state or federal law, then it sounds like you are out of luck here.