I have been receiving calls from a 6699 caller id.  they have been calling for a couple of days.  Due to the weird phone number, and no message I hadn't answered.  Today out of curiousity I did.  The told me that this was Dell calling, and had I noticed any erratic behavior on my computer lately?  I said no.  They asked me if I was the primary user, I answered yes.  He, the Indian caller then said we have reports that your computer has been downloading 100's of malicious softwares.  Right then I knew it was fraud...  and I said thank you, I'll run a virus scan and hung up.  I didn't want to be nasty, or argue in case they can hack my computer :)