There doesn't seem to be much value add from this guardian article. In fact, it kind of clouds the issue by rewording some of the complaints.
The actual letter. https://medium.com/@blindfb2020/facebook-empowers-racism-aga...
Maybe it was just me, but I had to read the actual letter to figure out what the issue was with the clean up request.
According to the letter, 2 white employees assumed the black/Latino employee was kitchen staff and asked the coworker to clean up their mess. When the black/Latino employee complained, the manager said they should dress more professionally. (like a t-shirt and a hoodie, maybe?)
