Richard Stallman:

Uber requires you to identify yourself, both to order a cab and to pay.
 Uber also records where you get the cab and where you go with it.
 The US government can get those records, and any lawsuit (such as a divorce lawsuit) can subpoena them.
 Uber’s clever policy of not being directly responsible for anything that goes wrong extends to harassment by drivers, and its practice of identifying passengers enables drivers to find out who the passenger is. This makes some women scared to use Uber.
 This problem comes directly out of the practices listed above that mistreat all users of Uber.

Via David Levinson.