I came across this quick article on having a 4-Way Sillcock Key in your preps to be able to access secured and restricted water supplies. In cases of emergency or those times when you have permission to access water from secure outlets but the person with the tool isn't available, this tool could be highly sought after.
http://www.geek-prepper.com/2013/03/16/secret-weapon-to-access-restricted-water-2/
This is a companion discussion topic for the original entry at https://peakprosperity.com/4-way-sillcock-key/