I am a software engineer in California. If I create a piece of software, in my own time, using my own equipment, do I own the copyright on that creation, or does my employer?
I see things such as "Google asserts copyright, even on work I do in my own time" (HN discussion). In the HN discussion, someone asserts,
California law is pretty clear, if you do it on your own time, on your own equipment, it's yours.
Sadly, he does not cite a source for this. The closest I'm able to find is in California's Labor Code §2870,
(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:
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
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.
However, this uses the text "rights in an invention"; does that cover copyright? (Is this the correct law?) Does "Relate … to the employer's business" cover the entirety of software engineering, or just the particular software engineering my employer does? Otherwise, what law is there that backs up the above claim, if any? Or does my employer own copyright on everything down to the love letters I write?