There are an amazing number of remote control applications out there, as I discover when taking the scam calls from 'The Microsoft Technical Centre' etc about how my PC is infected with bad downloads.
Mysteriously when they ask me to connect to x.y.z website and the 'security proxy' blocks it, they have a pretty big list they can go through.
One day I'll need to find a nuke-me PDF file of my credit card details for when they get to that stage of the scam script.