What is the significance of hanging shoes from a power line?

I will admit that I am not very knowledgeble of hip hop culture. I am not very interested in the music or the style just from a difference in taste, not that I have a particular dislike because of racial or cultural differences. I am not a hip hop basher, it's just not my thing personally. But I saw someone wearing a t-shirt representing the Brooklyn Nets that shows the word BROOKLYN across the front with shoes hanging from the letters. I later heard the shirt is being marketed as a means to show "pride in your borough". I am aware of the urban legend around hanging shoes on power lines, but not having grown up, or otherwise have lived that culture, I want to know what other people think about what message the Brooklyn Nets are trying to convey by selling this shirt. How does that shirt represent Brooklyn as a culture, as a community in general? What is Jay-Z trying to say by marketing this product for his team? How should Brooklynites that did not grow up in this culture take it (like my family -- white, immigrant, middle class, grandfather grew up near Ebbets Field)? I just want to be educated on something I don't understand, and how it is seen as a positive symbol to represent a professional sports franchise on this shirt.