Me: "Hello?"
John: "Hello sir, this is John calling from Windows support for your ISP. We have detected problem with your Windows PC sir, and you have virus or other infection"
Me: "Oh, really? Well I have 3 PCs. Which one is it?"
John: "It is the one running Windows Vista or Windows 7"
Me: "Well they all are. Can you give me the MAC address?
John: "Sir, it is your computer with Windows"
Me: "Yes I know, but if you have some sort of notification it'll have details like the version of the OS, processor speed, MAC address, that sort of thing. Can you tell me any of that?"
John: "Sir, there is no need for any of this"
Me: "Well there is, because I don't believe you. Can you even tell me the name of my ISP?"
John: "Yes, I am calling from your ISP"
Me: "Yes, and who would that be? I should point out that I work for Microsoft <note: I don't really> and so you might want to hang up now, because I know this is a scam."
John: You work for Microsoft? What is your employee number? Who is your manager? This is not a scam."
Me: "I'm not telling you that! You called me! What's *your* employee number?"
John: "No, give me *your* employee number."
Me: "Why should I?"
John: "Because I asked first! I will have you fired!"
Me: "You asked first? Is that seriously the best you've got?"
John: "You are a son of a beeeeeech <note: this is how he pronounced it!>"
Me: "Seriously?"
John: <hangs up>

Seems like son of a bitch/beeeeeech is currently the insult of choice in the more dubious Bangalore call centres!