You’re walking down an alleyway, minding your own business and keeping your face down on your phone. You pass by a group of men on sitting on motorcycles, talking to each other and smoking cigarettes. One of them, tall and tan, sees you walking by and nudges his friends, saying something you can’t hear into their ears. They all laugh and look at you with danger in their eyes, one of them whistling in your direction. You get a sinking feeling in your stomach, like something is about to happen.