So, pretty much anywhere you go in the US that has electrica/telephone cables strung along the telephone poles ... you'll find sneakers thrown so they loop over the cables that cross intersections.
Is there any urban legends/myths/folk tales about why people do this or what they mean?
ETA:Thanks everybody! It looks like the general, but by no means universal, meaning is related to gang territorial markers or drug availibility. With a few bullying behaviors, sexual escapades and military freedom options thrown in.
Which is great, actually, because that means I can use it to mean whatever I want in my 'near-future-supernatural-cop-story'.