California law is silent (last I looked) on who uses what bathrooms, which I find irritating, as neither the law nor local agencies discourage men from using the women's facilities and pissing on the seats.

Some particular venues -- the Oakland Colosseum is one -- do enforce internal rules using their own rent-a-cops, but this is by no means universal. On the other hand, to be perfectly fair, I myself (being the feisty sort) have "liberated" men's toilets on several occasions after standing in very long lines for what seemed entirely too long. Most men are fairly sanguine about such things, perhaps because they dimly perceive the injustice of current building codes which mandate grossly inadequate numbers of stalls in women's bathrooms, despite the fact that any idiot might notice long lines of women waiting whilst men waltz in and out of theirs at leisure.