This is going to sound .....y when I say it and I suppose it is - but I promise it is not personal.
I'm thinking it's karma for all of the butts that have flown out of your car window and littered the road, perhaps sparked a little fire or burned the hood of the car behind you. This is a huge pet peeve of mine when it comes to smokers. I may have done it in my teens but learned pretty quickly that it's disgusting, rude and dangerous.
Now onto the reverse dangers... I sit "Indian Style" with the keyboard on my lap. Since I've been vaping and don't have an ashtray to put my PV on, I actually hold it with my toes while I'm typing. Weird, I know. A while back I bought and smoked a pack of analogs and almost tried to hold one with my toes as if it were a PV.