27. Indianapolis, Indiana (3.1%)

A controversial sign was placed by one angry citizen calling out the residents of Indianapolis for littering in March of 2019. The sign was short, sweet, and to the point reading that “we love litter.”

Littering has long been a problem in the area, but this sign may have played a part in getting people to clean up their act. Keep Indianapolis Beautiful reported that it had collected more than one million pounds of litter in 2018.