At a previous job, software testers had to write reports every Mon/Wed/Fri on what they did and e-mail them to their supervisor.
One of them got pretty tired of writing the same shit, and was like 99% sure the supervisor wasn't reading the reports, so started adding "I don't think anybody is reading these. This is a waste of my time." right above his e-mail signature.
It took over 3 months before it got noticed. Supervisor wasn't pleased, but had to admit he was right. He still required reports, but only on Fridays.