A sign - shoe tossing

Did you ever see shoes hanging from telephone cables or power cables in your town? Well, in my town I noticed some, and I was always wondering why people do this? I didn't know how to look for it, but here is what I found out at the end. This is called "shoe tossing" in english. So, here is an rather large answer i got on the Wikipedia : https://en.wikipedia.org/wiki/Shoe_tossing

In my town, "shoe tossing" is a sign of a place where you can get some illegal stuff.
World is full of signs and symbols we are yet to learn.
It is rather peculiar when I started reading some of them.