In the period where Uber used properly-licensed black cars but competitors Lyft and Sidecar used ordinary vehicles, Travis Kalanick tried to get regulators to pursue Lyft and Sidecar. Uber leaders met secretly with San Franscisco transportation regulators to flag what they saw as violations. Source: Mike Isaac’s Super Pumped (p. 119). In addition, Kalanick personally blogged about the situation.
When Uber later launched UberX, with unlicensed vehicles much like Lyft and Sidecar, Kalanick wrote “We could have chosen to use regulation to thwart our competitors,” which Mike Isaac calls “disingenuous” in that Uber had in fact attempted to do exactly that.