A present-day Irish solution to "al-fresco urination": electrify your shop front.
http://www.irishexaminer.com/ireland/shops-shock-and-awe-pla...
http://www.irishexaminer.com/ireland/shops-shock-and-awe-pla...
QED via Mythbusters
Either way, I assume - crucially for the shop owner - most backed-up, drunken revellers would be unaware of this :)