On holiday i was walking between Soi 11 and Soi 15 when someone shouted "nice watch". There were 3 black guys sitting on a wall. I kept walking, thinking how nice and friendly of these guys to say that. (It was a nice looking but not expensive watch)
Since then i have never wore that watch again in BKK, and i am very wary when i see groups of black guys when walking in that area.