Public urination is illegal in most cities, for the very good reason that it's totally disgusting.
But, as you probably know unless you live in a very well-behaved convent, people do it anyway. All the time. In secret nooks and crannies, and in broad daylight on major roads and high streets.
So what are city governments to do? Of course, they could just build more toilets, and hope the problem goes away. But some have opted for more punishing solutions, aimed at shaming the penny-spending perpetrator or even soaking him (let's be honest, it's probably a him) in his own urine. Here are four of our favourites.
Hamburg's "peeback" wall
The residents of Hamburg's St Pauli neighborhood, home to bars, clubs, a red light district and a football club, were getting a little sick of nighttime revelers' tendency to urinate on walls. As one resident put it, "I'm really pissed off that people pee everywhere".
So a community group came up with a scientific solution: they coated walls around the neighborhood with a special hydrophobic material that repels the liquid back onto the feet and ankles of its human dispenser. This video shows several furtive pissers getting their comeuppance.
Rio's pee patrol
Every year, Rio de Janeiro's Carnival is awash with body paint, food and drink, and, thanks to a lack of bathroom facilities, urine. So, since 2013, the city has dispatched agents to spot and remove offenders from the festivities.
AfroReggae, one of the Carnival's organisers had another bright idea: their floats at the 2013 event contained turbo-charging urinals, which coverted pee into electricity, and so powered the float's sound system.
Click for a larger image.
Calcutta's "pissing tanker"
OK, so this idea didn't exactly come from the mayor's office. The video above, from YouTube account "The Clean Indian", shows men riding through Mumbai aboard a water tank truck, spraying public urinators with a large fire hose. They've painted the tanker yellow, with a special logo:
Image: The Clean Indian via YouTube.
Yes, the idea of unknown urine vigilantes wielding a huge amount of water pressure is a little ominous, as is the video's Upworthy-esque caption: "You won't believe what we did to people using the outdoors as a toilet".
Chester's historical walk of shame
As you'd expect, the UK's contribution is a little more restrained, though no less odd. Public urinators caught on CCTV in the northern city of Chester are given a choice: go to court, and risk paying a large fine, or agree to participate in a "heritage awareness course".
This, in case you were wondering, consists of paying £75 to watch yourself piss in public on CCTV, then undertake a historical walk through the city's centre while an expert explains the damage your excreta can do to various landmarks and cobbled streets. How terribly British.