coin operated valves pierced onto your personal parts

[inspectherwet]

All of you who declare,
"What'll they tax next?
Air!" understand that as far as politicians go
nothing is sacred (except perhaps their pensions).
If it can be measured and assessed, it can be taxed.
Add a crazed emperor into the picture and you understand
how something like the Roman pee tax came into being.

Entering the world around the first century AD,
the Roman tax on urine apparently began with that fount
of all depravity, the Emperor Nero of Rome.
Not content with pissing off the Roman citizenry
by spending their collected tax dollars on every
sort of self-serving luxury imaginable,
Nero decided to squeeze just a little bit more out
of his countrymen -- by imposing the pee tax.

Now before you imagine coin operated valves pierced
onto your personal parts, or morning chamber pots
being weighed and measured by squeamish officials,
it's important to note that this tax was in reality
levied against urine toilets.
I wonder where spend a penny came from.

[DeltaFoxtrot]

They still do the same today, albeit in a less direct manner, via waste water fees.

Of course why humanity is stupid enough to use potable water to carry away waste I'll never know.

[Sarrim]

The urine tax was collected as a service to the roman populace, who would otherwise need to carry said chamberpots out to where they could be disposed of properly. In addition, the primary recipients of said urine were key industries within the Roman empire, namely tanning and agriculture.