Use of Company Resources for Personal Gain?

[Guest sponger42]

In California, are there any State or Federal laws which cover the use of company resources?

If a company has no stated policy regarding the use of company computers:

If an employee were to use company resources to sell items on an online bidding service, assuming it's during their breaks, lunch, or after work, could the company make a claim against that employee?

If an employee were to use company computers to design a product--again, assuming it is on their own time--and then later use those designs to produce and sell that product, could the company litigate a claim against that employee?

Could someone point me to the appropriate part of California or Federal law that covers these questions?

Thanks!

Edit: It occurs to me that I am asking non-benefit related employment questions. I'm sorry about that. If there is a more appropriate place for me to be asking these questions, could someone please direct me there? Thanks!