I keep an old XP laptop loaded with furry porn, pictures of cows and pigs being slaughtered, BDSM porn, transsexual midget porn, stuff from rotten.com/ogrish like beheadings, gential mutilation, etc., set on random rotate every second for the desktop with a nice fading transition, everything locked except the remote assistance tool, and when they call I put that machine live and let them in.
The extortion begins, and then they see something that invariably offends the piss out of them while they're forced to watch a constantly-changing desktop wallpaper they can't stop, and the extortion ends with me laughing in their ears.
Endless entertainment. I even got a "You're the sickest thing existing on this planet." from some chick that was playing the scam.
I lol'd hard at that one.