In 2005, Mr. Vanderpooten unveiled a design for an anti-pipi wall, a jagged surface that splashes urine back onto the unzipped offender. The prototype was attached to a wall in one of the most affected areas at the time — a street called the Cour des Petites Ecuries on Paris’ Right Bank. Mr. Vanderpooten says he often goes by to check on his experiment: ‘The people who used to pee there don’t pee in the same place anymore.’ The city has no immediate plans to erect more of the walls.
