Okay, just for you.
There was this young fella walking the neighborhood "selling alarm systems". Was he legit? I don't know. He was wearing a badge around his neck but c'mon, any retard can print a badge nowadays.
What arose my suspicion was that he kept insisting on entering our residence.
Since I was doing some yardwork and was curious about his motives, I invited him into the backyard. We sat on a bench and he was asking innocent questions about number of windows, doors, rooms, high-priced electronics, location of jewelry ... lol ... poor bastard didn't know what was coming.

He finally managed to offer a quote for an alarm system and proceeded to describe all the features and perks and how the main console would hang on the wall in our bedroom and will be programmed to call 911 if we press the Intruder button. I inquired whether the number is hardcoded or whether it can be reprogrammed. His eye opened a little bit with curiosity: "why, you mean you want it to call your cellphone or something?" To which I calmly replied: "Nope, there is no need to call emergency services since there will be no emergency. I would rather that it call the Coroner's office so that they can come pick up the dead body. And my next call would be to the cleaning service to come take care of the blood on the floor."
The kid's eyes were huge, he barely thanked me for my time and we have never seen him again.
Mind you, we have an alarm system and a sign that says so right in front of the house. Why oh why do I like screwing with crooks?

Probably because it gets the message across that this residence is defended.

I believe in crime prevention.
That's a good story.
You know what I really hate is door to door salesmen, especially the high pressure ones. The worst ones are the ones that want to sell you some product based on bunk science or public hysteria.
Case in point: Some magic magnet home water treatment system.
Knock knock. "Who is it?"
"Water treatment distributor. We're offering a free water test."
Okay. I know where this is going. I just want to f*** with the guy. "Come on in."
So the guy goes in to the kitchen, opens the tap, and pours a little water in some sort of small electronic gadget with a digital LCD display, then reads it. "Oh, my" he says, shaking his head, "It's a nine."
"A nine.....what?"
"A nine, we're looking for a one ideally, and a two to three max."
"I mean what units are you talking about?"
"Oh this measures the water quality on a scale of one to ten. It's a relative scale. Anyway, we have a product which will remove....(blase, skipe, blase)... and I'll prove it. Let's just clamp this demo unit on the faucet here like this, and flow some water through this, and put it in here and.... see, it came out a one! So you KNOW it works!"
Big f***ing surprise. "Hmm... lemmie see that." Sniff sniff. Taste. "Looks, smells and tastes the same. Which, quite frankly, while it isn't bad, it isn't the greatest either."
"But, but it's pure now. It's a whole lot healthier for you."
"What did it remove?"
"It removed all of the impurities, you know, the stuff that is in the water and that the water company puts in there too."
"What does the water company put in?"
"Chlorine...and...stuff. Anyway...."
"Let me see something. Let's put a little of that pure water on a plate here." Click, click, light. "Okay now let's heat this up a bit and boil it off. There we go. Well look at that. WTF is this ring doing here?"
"Uh, that's uh, all water leaves that after it dries and..."
"I thought you said your device removed all of the impurities?"
"It did.... uh, that's not an impurity."
"Then what is it?"
"It's uh....anyway, we have a special pricing promotion going on but it's only effective for........"
I kept the guy there for about an hour and a half. In that hour and a half he learned all about hardness, pH, alkalinity, breakpoint chlorination, and the various processes to remove different contaminants from water. He was literally begging to leave. Funny, I never got solicited by that company again.