I remember years ago, when I was pg with my first. I was in the que in the post office in Kentish Town and a young black guy was behind me. Noone was thinking much about anything, then a young white rasta comes in, and starts racialy abusing this guy.
It was shocking, multiple N words, the lot. He was trying to goad this young guy in to a fight so he coudl beat him up (the white guy was bigger (and, well fucking nuts))
He was accusing the black guy of staring or laughing at him (which he had not at all)
It was obvious that an acutal black person triggered this nut.