There was a piece on the Today program this morning during the Business Update about those nuisance calls. One of their business correspondents got one of these calls, so he taped it and they played some of it on-air with a warning that people should hang up if they get one
The BBC guy (who uses a Mac), strung the bloke along for 10 mins before telling the bloke he wasn't on a Windows machine - then asked for his phone number so he could complain to his supervisor. The bloke then had a rant about time wasters and hung up.