There's not much love lost between Facebook and Google these days, but the companies are joining forces in one area – fighting two online-privacy bills that are moving through the California legislature.

One of the bills, a "do not track" proposal introduced by State Sen. Alan Lowenthal, would require companies to let people opt out of having their online data collected. The other, by State Sen. Ellen Corbett, would require social-networking sites to keep users' information private by default and to remove personally identifying...