Are they medicine bottles? From an article:

You won’t find a pair of shoes hanging from the power lines high above 8th and Lincoln in Central Richmond. Instead, orange and red cough syrup bottles dangle from ropes flung across the wires, a signal that hits of codeine are sold on this street.

“It’s a trendy drug,” Richmond Police Officer Tony Diaz said, as his patrol car passed slowly under the bottles. Diaz and his partner, Officer Matt Stonebraker, said they see prescription drug abuse in Richmond all the time. Drinking codeine is as common as smoking a joint of marijuana, they said.

Richmond, like cities big and small across the country, is experiencing a rise in prescription drug abuse. According to the 2010 National Survey on Drug Use and Health, prescription drugs are the second-most abused drug in the nation, behind only marijuana.