urine lobbing 

To throw a cup, bottle, plastic bag or any type of container that has piss in it at somebody. Urine lobbing is quite popular at soccar games south of the Rio Grande border. Often times poor people in the balcony or upper stands will urine lob at rich people down below. Urine lobbing happens at concerts, sporting events or assholes that have a crowd of people below them.

I saw this freak at a GWAR show up in the balcony, pissing in a cup. He then threw the cup of piss at the crowd below.

urine lobbing by Paul Della Valle August 24, 2004