I'm a white guy from a fairly non-diverse city. I was at a grocery store today where a cashier opened up their line to serve me and, I thought, the person behind me. As they were serving me, though, they put up their lane closed sign right in front of the black man behind me. The buy was just trying to purchase some tuna, bread, and peanut butter.

The cashier basically decided to serve me, a middle class white man, but refused to serve the black man behind me. I was so shocked that I didn't say anything. It is possible that I misunderstood the situation but it seemed so blatant.

What should I have done in this situation? Should I have spoken up? Would that have just been more embarrassing for the man who was being discriminated against?

Honestly, I'm still just in shock to see someone treated so poorly when they were simply trying to buy food for themselves. I recognize that means that I'm sheltered but I also feel like I should be able to use my unearned privilege to help others who are being discriminated against.