What are you talking about? Normal, non-rich people totally have the same expectation of privacy when they take a cab. Would YOU be ok if your cab driver films you without any knowledge? A taxi/uber/lyft is a rented private car, it is not the same as public transportation.
Most taxis I've been in the past, oh, let's say 15 years, have had interior/passenger cams.
Edit: This seems to back up my understanding that most states are 1-party consent. http://www.dmlp.org/legal-guide/recording-phone-calls-and-co...
"In its majestic equality, the law forbids rich and poor alike to sleep under bridges, beg in the streets and steal loaves of bread."
This isn't true, and even if it were---cabs are private spaces; that's what you're paying for. Subways, elevators, busses are shared public space.
To me this is a very classist oppinion. Normal people are filmed as they take the bus, ride the subway, go on the elevator, walk through the graveyard (seriously), go shopping, so why should a rich person who can afford a cab be granted an exclusive right to privacy which the rest of us don't have? If we promote this case due to the expectation of privacy that only serves to create this devide between rich and poor in which only the rich can afford privacy rather than a precident in which everyone deserves it.