story
Theoretically, if the company can get a bunch of phone #s, they could even completely anonymize it by assigning two temporary numbers (one to driver, one to passenger) and call-forwarding them for the duration of the trip. I havent' checked but I doubt anybody actually does this. And in the absence of this level of anonymity, I would at the very least expect a car service app to require you to place the call before giving you the phone # of the other person.