I literally just hung up on one of those calls. This is their third attempt. But last night I got hit by one of those fake spyware removal tools. It immediately took over told me I was infected, stopped me using my task manager, tried to delete my anti virus, blocked my spyware tools. Downloaded it's own 'anti virus' program and hit me with a fake Microsoft security centre warning. After a bit of googling I managed to download PC doctor in safe mode as it disabled my first attempt at downloading and with spybot got rid of the pest. I was up until four in the morning doing it though. Coincidence? You decide!
I'm not overly savvy with PCs but my BS meter is well calibrated. I've had issues before but never one as complex as that.
My PC is clear today but slow as hell as I have everything on to protect it.