The number of TLC cars has skyrocketed recently. Which, in many important ways, is a good thing. But this is a crowded city, literally everything that is at risk of runaway growth in this city is regulated, and for good reason, all the way down to hot dog carts.
This city could rapidly be unlivable otherwise. The growth of TLC cars has created obvious problems, they are often oblivious to their surroundings, blocking streets while they stare at the screen trying to find a pickup, creating localized congestion, etc.
I'm not sure if a numerical limit is the answer, or geographic restrictions, or who knows, but what it sounds like is the city is starting to think about it. Good.