And you refuse him based on what? The Axiom of Choice? Because if you refuse him for being Asian and you are consistent you have to refuse all Asians. Because if you refuse 8chan because some killers used the service you will have to refuse Facebook, Twitter, All major Hollywood Studios, the Catholic Church, the GOP, the DP, the Saudi Arabia government and thousands of more organizations which directly or indirectly had a role in many crimes.

You don't seem to understand. You can refuse to do business with someone because you don't like the color of their tie.

In many countries, there are specific protected classes and you can't refuse their business just because they are a member of that class. Confusing these concepts does not help the argument.