It's easy to hang up or tell them you're not running Windows and make them hang up - but if you want to get in to competitive sport, surely the game is to see how long you can keep them on the phone (wasting their time) before they catch on. Seeing these stories of letting them have full access to your computer though... no, that's too dangerous!

I usually just say "no thank you" and put the phone down. Linux user here anyway, but I don't want to waste *my* time...