What rights does the "captive audience" have to privacy rights?

Assuming City's decision to limit advertising sign space to commercial material requires a strict scrutiny review, we have no hesitancy to find the privacy rights of the "captive audience" justified the exclusion within transit buses of all forms of expression which could not otherwise be restricted. California has constitutionally memorialized the right to privacy (Cal.Const., art. I, 1), and although that right is not absolute (People v. Stritzinger (1983) 34 Cal.3d 505, 511, 194 Cal.Rptr. 431, 668 P.2d 738), its role in public transportation deserves fair consideration. (See People v. Cook (1985) 41 Cal.3d 373, 221 Cal.Rptr. 499, 710 P.2d 299, privacy extends into some otherwise public spaces.)