Legal Question in Employment Law in California

No. This would violate just about any reasonable expectation of privacy I can imagine.

I don't often disagree with Mr. Kirschbaum, but do this time. If you bring something onto company property, you lose almost any expectation of privacy in it, with few exceptions. As an example, the company is free to demand inspection and search as you enter the door or gate as to you, your briefcases, lunch box, etc. They are free to search your desk, locker, backpack, briefcase or purse on site - with 'reasonable suspicion'. You can certainly claim 'privacy', but have limited legal support for it outside of the area of bathrooms or dressing/changing rooms. In the criminal context, if you are found with contraband and the company calls police to have you arrested, the 'search and seizure' rules that prevent police from doing things, do NOT apply to private persons or employers, and what was found could arguably be used in evidence at trial.

I never argue with the man holding the gun. I would agree the employer has the right to search its own property, such as a desk, locker, company provided computer, etc. But I think case law has drawn the line with personal property. If I had a purse (not that I do) and left my desk to go to the bathroom and came back to find someone had gone through it without my permission, I think they crossed the line. Same with a backpack. Yes, they can ask if there is reasonable grounds, and probably fire the employee if they refuse. But to search one's personal property, without the person being present or having their consent? In my opinion, they went too far.