>Barring those agreements states, like California and Washington, explicitly have laws giving workers rights to their work done without using company resources.
California's law only covers things which are not related to the company's current or future anticipated business. For a company like Facebook or Google that covers so much ground that the law may as well not exist.
That's not true. California law covers everything you do outside of the work hours without employer-provided equipment, including things in the employer's areas of business. What California does allow the employer to do is to have a conflict of interest provision that will allow it to discipline or sue you if you do something outside of work hours that could cause conflict with the employer's business. They won't own your IP though.
Can you cite a source for this. Reading the relevant law it says that the IP clause is valid in cases of conflict with the employer's business. If the IP clause is valid then, as I read it, they legally own your IP as you assigned it to them in a valid contract. They may need to sue you to exercise their right but if they win they gain your IP.
>(a) Any provision in an employment agreement which provides that an employee shall assign, or offer to assign, any of his or her rights in an invention to his or her employer shall not apply to an invention that the employee developed entirely on his or her own time without using the employer s equipment, supplies, facilities, or trade secret information except for those inventions that either:
> (1) Relate at the time of conception or reduction to practice of the invention to the employer s business, or actual or demonstrably anticipated research or development of the employer; or
California's law only covers things which are not related to the company's current or future anticipated business. For a company like Facebook or Google that covers so much ground that the law may as well not exist.