I find myself really irritated when a customer writes a nitpicky hypercritical email and then I waste a whole SHITLOAD of time replying to the guy who doesn't appreciate us as much as the members who are HAPPY with our work who I rarely spend as much time writing to. Then what really REALLY annoys me is when their fucking email addresses are wrong or they have some stupid-ass email service or internet provider that refuses to deliver the email.
SO. FUCKING. LAME.