Just in case this site hasn’t given you enough reasons to think twice before leaving a passive-aggressive note, Tobjar in Oakland, California passes along this cautionary tale from worsethanfailure.com:

Not too long ago, there was a small furor in the local media about a major disaster at The State’s Technology Services Division.…When employees of The State came in to work following a three day weekend, they found their workstations overloaded with “cannot logon” and “Exchange communication” error messages. The Network Services folks had it even worse: the server room was a sweltering 109° Fahrenheit and filled with dead or dying servers….They worked day and night to order new equipment, build new servers, and restore everything from back-up. Countless overtime hours and nearly two hundred thousand dollars in equipment costs later, they managed to bring everything back online. When the Exchange servers were finally restored, the following email finally made its way to everyone’s inbox:

As for the employee who sent it, he decided to take an early retirement.

related: When Ph.d.s get frustrated