For a while, I was getting calls from some company that wanted to install a free security system in my home. It took about 10 minutes on the phone before I was able to get the guy to mention that there was a monthly fee for monitoring the system. But, fwiw, apparently there are companies out there who install the system for free, then make their money from the monthly fee instead.
I wasn't actually interested; it was just that I had at least a dozen phone calls from them, all from different cities/numbers. Finally, I talked to the guy for about 15 minutes. At least I did amuse him for a bit with my free home security (he was confused how my system was free) - "Well, if someone who doesn't belong here goes into my house when I'm not home, my always home retired neighbor will confront them and shoot them if he has to. We've already had one trespasser shot in my front lawn, though it wasn't a human. And, I reciprocate. I bury the bodies; I have the digging equipment." He went right in to, "well, what if you have a fire in your house?" "Then, when my neighbor sees the flames and smoke, he'll call the fire department. If my house burns, I'd rather it all burns - I'm insured. And, if I'm home, when the smoke and heat alarms go off, I'll call, plus I have at least half a dozen fire extinguishers." He persisted: "what if you can't get to your phone?" "It's in my pocket. Are you saying that there's going to be a fire, and my arm is going to shrink to half of its length, all at the same time? That's a heck of a coincidence." "What if you have a heart attack?" "My wife is a well trained nurse; she has worked in an ER. She would know how to care for me better until the ambulance arrives." "What if your wife has a heart attack?" "I have her insured for a lot of money."
After 15 minutes, I told him that I was just joking around to waste his time because I was tired of the phone calls. If they didn't take me off the call list, I'd waste 30 minutes of their time the next time. I haven't received a call since; ditto calls for a couple of other services that I got at least once every other day.