What Do Sneakers on Telephone Wires Really Mean?

In Australia, dangling sneakers mean you've lost your virginity, in Spain, they are a territorial gentlemen's agreement between the mafia and the police, and in the United States they can signify bullying, street art, or possibly a crack house.

http://www.theatlantic.com/entertainment/archive/2013/08/what-do-sneakers-on-telephone-wires-really-mean/279146/