‘heard tennis shoes hanging over a power line meant you could buy crack there.’

‘In some neighborhoods, shoes tied together and hanging from power lines or tree branches signify that someone has died.’

Wired Soles

‘Old running shoes hanging from trees and power lines are ‘gang signs.’

‘Throwing a pair of shoes up into a tree can also be celebratory act. For graduating seniors.’

‘The purposes for hanging shoes in trees can be negative. Stealing the shoes of younger, weaker or overweight children and throwing them up into an inaccessible location.’
‘The shoes can serve as turf-markers, indicating that an area is under the control of a particular gang.’
‘Some artists establish their own shoe trees, starting with bare trees and adding pair after pair of shoes. The goal of such actions is usually to create a living, evolving art project which other people can openly contribute to by hanging their own shoes.’