Why do my neighbors wash the dirt from their balconies onto my windows?

Why is it called a "loo?" 

The British word for toilet, "loo", derives from the French "garde a l'eau!" In medieval Europe people had little conception of hygiene and threw the contents of their chamber pots out the window into the street below. In France the practice was preceded by shouting "garde a l'eau!" ("Watch out for the water!"). In England, this phrase was Anglicised, first to "gardy-loo!", then just "loo", and eventually came to mean the toilet/lavatory itself.

 Some of the residents of my appartment building seem to believe they are in medieval Europe. Throwing dirty water off your balcony or letting it drip out through the drainage holes and onto the windows of your neighbours below is NOT ACCEPTABLE in modern North American society. It is dirty and disgusting.

Do these people not know how much money the building pays to have the windows washed twice a year?