It's really so easy and the results can be very satisfying. I am posting this at some risk but I want to contribute to solving this problem.
First understand why this still happens even with so many Black taxi drivers and so few white taxi drivers. It is because experience shows that overall it is more economically productive to pick up white, latino and Asian passengers than it is to pick up Black passengers. That hasn't likely been proven in any study but thousands of taxi drivers will tell you the same thing. They will also tell you that non Black passengers as a whole present fewer problems in general. Taxi drivers believe these things. It might not be fair it puts a whole group of individuals into a " bag" that is created by a relative few people but there it is. Deal with it?
New York City and State have really great laws and regulations against all kinds of discrimination. They just don't get much enforcement. The rules for taxi drivers sound strong and strict and if Michael Bloomberg had ever actually wanted to he could have cut these incidents by 80 percent by enforcing these regulations. It isn't as though you are complaining about the weather. Something actually could have been and still could be done about it.
Okay the reality is this situation doesn't bother Bloomberg much at all. So what can you do about it?
Call 311. Get the drivers medallion number off the roof light (it will be something like 9X99) and any other detail like the date and time of the incident and if possible - but not really necessary- a description of the driver, his name, his hack number. The basic thing you will need is the medallion number and the time and place of the incident.
Hack number helps (something like 6330993) but you don't need it.
You will have to file a complaint. CALL 311.You will not have to go in person to a trial.
Punishment will be swift, certain and no joke to the driver. So please pass this information around and follow through.