Many years ago, I was occupying a desk on the corner of a college's IT facility. For some reason, any phone call for the department would be routed to my desk, and I spent a good proportion of the day fending off calls from would-be suppliers of wonderful gadgetry and utilities for making our lives simpler, if more costly. It was fairly easy to deal with such callers, all you needed to do was to give them a kind of ball park idea of the size of our equipment budget, and they would not bother us again.
One day, however, I was assailed by a new breed of salesperson. This was the kind for whom an apparent lack of funds was not a problem. He called and asked if he could speak to whomever was in charge of the IT facility. At the time, by default, that person was me. I asked what I could do for him.
He started talking about security products, asked if we had Windows, and proceeded to talk at length about theft. My previous conversation had been on the subject of those old-fashioned kind of windows, the type that Dr. Johnson, in his early dictionary, described as "An orifice in an edifice for the intromission of illumination or ventilation" and I'm afraid that I was still in that sphere of thought.
So, when he mentioned his product, "Latches for Windows," I cut him short by saying that we had no need for any such products, all our windows were perfectly secure, thank you very much.
Some time later, the professor to whom, in theory, we reported, arrived at my desk side to inform me that I would be getting a call from a software rep who had a product that could help us to secure our systems. – Remember, this was in the days of Windows 3.11, which was as secure as a wet paper bag.
The prof was very keen on having this system and had arranged for the rep to call me. Sadly, he failed to mention it to me, so when the call came it was dealt with by my usual technique, a method called "Dumb Ignorance," a method so effective that I have patented it.