Silicon Valley tech companies in California require employees to sign a contract that assigns all inventions to the employer. The only protection employees have are in the form of [Section 2870 of the California Labor Code](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=LAB&sectionNum=2870) that states the following:

> 
> (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
> 
> 
> (2) Result from any work performed by the employee for the employer.
> 
> 
> (b) To the extent a provision in an employment agreement purports to
> require an employee to assign an invention otherwise excluded from
> being required to be assigned under subdivision (a), the provision is
> against the public policy of this state and is unenforceable.
> 
> 
> 

If an employee quits and then launches their own product that relates to the former employer's business, can that former employer sue the former employee and try to claim rights to the product **solely on the grounds that the invention relates to their business?** Even if the former employer has no evidence that the former employee used company equipment or developed it on company time?

For example, could the former employer claim the former employee could not have come up with such a product unless they did it while working at their company and place the burden of proof on the employee to prove they came up with the product either before or after the time of employment?

What if the former employee did not know that their company had a similar project in the works while employed there?

I am worried about large aggressive Silicon Valley style former employers overstepping their bounds to try and claim ownership of former employee's post-employement projects.